Can I use my heat anticipator setting to reduce short cycling?

TGALL

I have a Weil McLain SGO-4, which today discovered is oversized. My 12 radiators add up to 326 EDR. I calculated that I need 78,240 BTU / hr. The Weil McLain is rated for 108,000 BTU / hr. ( 450 sqft of steam) . I recently corrected the pressuretrol so that it stops the system at 1.5 lbs and then starts back up when it drops to 0.5 lbs. I screwed it down to the lowest setting before the screw comes loose. And put the differential at 1. I like the way it is working now. Before I did this, the furnace guy had the system hitting 5.0 before it would cut out. He had the differential up to 3. and must have had the cut in at 2.0. Anyway, with the slightly oversized furnace and the high pressure setting, my vents were going crazy. That part is much better now.

But, my furnace still needs to run a long time because the smallest radiator is in the room with the thermostat. So, I still hit the 1.5 lbs of pressure before the thermostat stops callings for heat. I probably hit the 1.5 lbs of pressure 3 or 4 times before the thermostat gets satisfied. I believe this is called "short-cycling"? I am looking to get a bigger radiator for the room with the thermostat and that should heat the room quicker, but I was wondering why I just don't make the thermostat more sensitive so that when the temperature hits 71 degrees ( I set it at 71) it stops immediately rather than stoping when the room hits 72 degrees. I don't understand why the honeywell heat anticipator should be set at a high setting (1.2) for oil heat. The radiators stay warm (throwing heat) well after the furnace stops. Do you think I can set this much lower to say (.4) which is the setting for electric heat? Am I experiencing "short-cycles" ? or is hitting the pressure limit 4 times each time heat is called for normal? My radiators heat up right away. All 12 radiators are hot to the last section before the 1st shut down due to pressure. 1st time posting here. Just joined today.

Fred

That 1.2 anticipator setting is typically correct for steam heat. That setting minimizes the number of times the thermostat calls for heat by increasing the temp variance by some fraction of a degree, downward before a heat call is made. Lowering the anticipator will narrow that variance and cause the thermostat to call for heat more often.. If the room where the Tstat is located has the smallest radiator, I would suspect the other rooms are getting warmer than 71/72 degrees. If that room is comfortable, with the smaller radiator, you might try a couple things. 1) If that Thermostat has a mercury bulb in it, make sure the thermostst is perfectly level. If it is not setting level, it will throw the Tstat off and may explain why the temp goes up to 72 before cutting the boiler off. After leveling the Tstat, if that doesn't fix the problem try 2) try setting the anticipator to maybe 1.0 and see if that does the trick. If that still doesn't solve the problem, consider moving the tstat to a room that better reflect the true temp of the rest of the house.

The closer you move the anticipator to .4, the more often the tstat will call for heat, to a point where the boiler may not run long enough to be effective/efficient at warming the entire house.

Fred

One other thought, make sure you have good venting on the steam mains. If the venting is minimal, on the mains, that will cause the boiler to run for a longer period trying to push the air out of those mains.

Jamie Hall

Fred said:

One other thought, make sure you have good venting on the steam mains. If the venting is minimal, on the mains, that will cause the boiler to run for a longer period trying to push the air out of those mains.

And cycle more on pressure. Which is what you are experiencing. And yes, that is referred to as short cycling. Unfortunately, even with really good main venting, your boiler is enough oversize that that is likely to happen anyway.

Make sure that your main venting is ample -- that will help.

To sort of amplify of some of @Fred 's other comments, though -- check the temperature in the rest of the building. If it is warm enough, you can try turning the thermostat down a degree or two. That might help a little. Also, avoid setbacks -- keep the temperature at one setting.

Lastly -- don't be too concerned about the short cycling. Yes, it does reduce efficiency a little -- a point or two -- but so long as the off part of the short cycle is relatively short -- no more than a few minutes -- that's the worst of it.

TGALL

Great feedback. Thanks so much. I do want to make sure my mains are venting good and fast. I will call a professional in to replace them both. (i have 2). The one I know works good, I put some kids blowing bubbles on and it blew out a nice bubble. The other one, i couldn't be sure if it was venting or not. I was concerned because it seemed to have to much venting taking place on my radiators. I will check this all out again as the day I checked was the day that I lowered the pressuretrol.

Good to hear that short cycling is not that bad. I get a consistent 1 minute 50 seconds on the "OFF" time. And, then comes back for 3 to 4 minutes "ON" time.

Yes. the other rooms do get warmer than 71/72. I think that is what I am looking for. I want the boiler to run for shorter length of time. That will result in less times hitting the 1.5 pressure limit. Fewer short-cycles. And the other rooms will over heat less.

Thank you for all the information and the tips. I am going to experiment with the heat anticipator (Honeywell T87F) at different settings (1.2) (1.0) (0.8) (0.4) on a typical cool day 40 degrees outside. And, I will monitor how many calls for heat and number of short-cycles within each call for heat. And, give the results to this board for review and comment. After all... I don't want to increase my fuel bill just to avoid a few short-cycles.

Thanks everyone.

Fred

What vents do you have on the Mains? Keep in mind that because they are venting, that doesn't mean they are large enough to get the air out of the mains as quickly as you may need them to to help prevent longer boiler run times and, consequently greater pressure build up. How long is each main, what diameter pipe and what type vents are on there now? You always want to vent mains fast and radiators slowly. You can't over vent a main, albeit you will get to a point of diminishing return.

TGALL

@hatterasguy -- thanks, yes. I increased the venting on the small radiator this morning. This should help a little. It was one of those cheap adjustable types. It was set at 1/2 now I have it set at open full.

I will get back to you all soon with the timings. Over this weekend at some point.

Fred

Be sure you don't vent that radiator so fast that the steam races across the top or bottom of that radiator closing that vent leaving the bulk of that radiator cold. That will only compound your problem. Getting the air out of the mains with proper venting on the mains is the best approach.

EBEBRATT-Ed

All the above may be true

but the more obvious fix (or partial fix which will lengthen the cycle) is to down fire the boiler to a smaller nozzle. Depending on what burner you have you may have to change the burner end cone. Get someone competent to do this.

Short cycling should be avoided as much as possible. It's hard on the burner motor and ignition system, reduces efficiency and causes more soot from frequent starts and stops.

Chances are very good that you can easily drop 1 nozzle size below the boiler rating with an increase in efficiency and a reduction in cycling without changing any parts except the nozzle.

TGALL

This fall, I asked the serviceman to put a 1.10 Delavan 60B Nozzle. I wanted to go with the exact burner/boiler combination that was specified. I don't know if he did. It was the same serviceman that I asked to have the pressuretrol as "low as possible" and as you know, I lowered that myself after having the vents hissed so much and a 5.0 lb reading.

Are you saying that I could put in a 0.85 Delavan 60B, which is the nozzle used for the SG0-3 and Carlin EZ1HPW burner?

Or is there something in between the 1.10 and the 0.85? I guess a 1.0 like you said? A steam rating of 368 would be perfect.


The main vents are Gorton but at least 8 years old by now. I will replace the 2 main vents ASAP.

The "cheapo vent" in the room by thermostat is. I is made by Durst. I have some better ones (Gorton and Hoffman) on some of my other radiators.

The system came on after not running for a few hours.
15:00 steam hit all radiators but not filled them all yet
33:00 all sections of all radiators hot and pressure hit 1.5
off for 1:40
on for 3:45
off for 1:41
on for 3:40
off for 1:48
on for 1:10 until temperature hit. temp in room raised to 73
thermostat set at 71 and have the heat anticipator set at 1.0

It is 32 degrees outside. No wind that I can see.

The thermostat has not yet called for more heat it raised the temperature to 73 over 1 hour and 10 minutes ago. Looking at the thermostat I think I have another half hour or so before it will call for heat. so about 2 hours between heating cycles at 32 degrees with no wind.

New England SteamWorks

I think you need a lot more venting on the mains. On a 32 degree day with the thermostat set at a constant temp you should be able to maintain temp without short cycling, even given the size of the boiler. This assumes your mains are insulated, as they should be.

You do want to get this problem solved. I agree that the short cycling is not good for the burner.

Big Mouths. You might need 4. Spoke with Peter yesterday, he says there will be more in next week.

EBEBRATT-Ed

Put the ,85 nozzle in and tweak the oil pressure up a bit.

We are getting blinders on our eyes about venting and adjusting pressure controls. I don't care how many vents you put on or how you adjust the pressure control.

IF THE BOILER OUTPUT EXCEEDS WHAT THE RADIATION AND PIPING WILL CONDENSE THE BOILER WILL BULD PRESSURE AND SHORT CYCLE NO MATTER HOW MANY VENTS YOU HAVE OR HOW MANY PRESSURE CONTROL ADJUSTMENTS YOU MAKE.

The trick is to tweak the boiler so the output matches the radiation load + a tad for piping and pickup and then fix the venting.

The boiler then will most likely never build pressure, you will save fuel, burner ware & tare, smoother operation, less noise lower stack temp, better efficiency and a more stable water line.

The burner sitting idle for only 2 min. is not good

TGALL

I just have to read up on a smaller nozzle because I don't understand the concept and don't like doing things without having some sort of understanding. Will read up today.

This mornings observations...

The 2 main vents are Gorton Air Eliminator #1 the sit about 18 inches up. pipe sizes look big compared to my prior home that had the same exact furnace. No insulation directly around the furnace Copper Piping, but then yes to insulation on what looks to be steal pipes across the ceiling of the basement.

Except one! no insulation on the line that leads to the side of the house where the small radiator and thermostat is.

This mornings heat cycle was a little better. 33 degrees outside. Set the heat anticipator to 0.4 Total heat cycle was 43 minutes. a 28 minute full cycle. followed by 2 full short cycles (3:50 ON 1:40 OFF) and then a half short cycle completed the job.

Took better measurement on when each radiator heats the 1st section and last section of each radiator.

The small radiator (23.4 EDR) lags the earliest and largest radiator (42.7 EDR) by 8 minutes.

So it looks like I am going to ...
1. Get 2 new Main Vents installed and ask my professional installer about a smaller nozzle.
2. Insulate the pipe that leads to small radiator ( this will be tough, basement is a mess and its behind a sheetrock wall.
3. Keep the heat anticipator set at 0.4 (it goes off quicker this way - 1 less short-cycle)
4. Get a bigger radiator for the room with the thermostat (not going to move the thermostat, I like it on that interior wall in my dining room).
5. Try different vents on the small radiator to try to get it to heat faster.

Except for # 3 above, all this stuff should be done regardless of situation.

If I can get that small radiator to heat faster, I will only have 1 short cycle on a 32 degree non-windy day per heating cycle. And then with the new main vents, maybe no short cycle. And from what I hear... a new smaller nozzle properly fired may fix it by itself.

TGALL

@EBEBRATT-Ed - I did ruin 1 burner already. That is why I have the Carlin now. The 7 year old Beckett died on me.

New England SteamWorks

EBEBRATT-Ed said:

IF THE BOILER OUTPUT EXCEEDS WHAT THE RADIATION AND PIPING WILL CONDENSE THE BOILER WILL BULD PRESSURE AND SHORT CYCLE NO MATTER HOW MANY VENTS YOU HAVE OR HOW MANY PRESSURE CONTROL ADJUSTMENTS YOU MAKE.

This is true. But it will only do so if given enough time. On a properly vented/insulated system the over-sizing in this case is not sufficient to cause short cycling if set backs are not utilized. There won't be enough time.

Fred

@TGALL , It seems to me like you are trying to trade one problem for another. With the Tstat set at .4, you now seem to be over-shooting the house temp by an additional 2 or 3 degrees. That's not what you want (or at least not what I'd want). Do the main venting first and I can tell you, unless you have very very short mains, one Gorton #1 on each main is no where near enough. The whole principal behind good main venting is to eliminate the extended time the boiler has to run pushing all that Main air out through the small radiator vents. That shorter run time will likely reduce/eliminate the short cycling.

TGALL

@Fred, I thought the .4 setting would prevent me from over-shooting. I thought the 1.2 setting would make me over-shoot more. I guess I don't understand that, but my testing shows the thermostat is more sensitive with the lower setting.

I am doing the main venting. That is 1st order. Question .. Should I replace the Gorton #1 (s) with new Gorton #1(s) or should I try Gorton #2(s) ?

Fred

TGALL said:

@Fred, I thought the .4 setting would prevent me from over-shooting. I thought the 1.2 setting would make me over-shoot more. I guess I don't understand that, but my testing shows the thermostat is more sensitive with the lower setting.

I am doing the main venting. That is 1st order. Question .. Should I replace the Gorton #1 (s) with new Gorton #1(s) or should I try Gorton #2(s) ?

That .4 setting is geared more for forced hot air where the heat is almost immediate and there is no residual heat/mass after the blower shuts down. As I indicated in my first response, 1.2 is typically the better setting for steam as the "anticipator" is designed to shut the boiler down a little before reaching set point, "anticipating some residual temp rise from the radiators to bring the room temp up. Even at that, you were still a degree off and that is why I suggested you make sure the tstat is level. That Tstat has a mercury bulb in it and if the tstat isn't level, it will throw the temp off. There are two tabs on the top of that Tstat, under the cover plate that allows you to put a small level on it to level the tstat.
I would not replace the Main vents with Gorton #1's. they are simply too small for anything but the very shortest of Mains. I would replace them with the Barnes and Jones BigMouth vents. Much better built than the Gortons and one Bigmouth has the venting capacity of about two Gorton #2's. The cost of the Bigmouth is a little less than one Gorton #2. The best bang for your buck, for sure. They can be ordered from Amazon but I see they are out of stock. @Sailah indicated he has some at the factory and he can probably take an order and get them shipped to you They are $75.00/each:
https://www.amazon.com/Barnes-Jones-Big-Mouth-Vent/dp/B01F26P13C/ref=sr_1_fkmr1_1?ie=UTF8&qid=1483230144&sr=8-1-fkmr1&keywords=Barnes+and+Jones+Bigmouth

TGALL

@Fred , thanks. I take your advice an now set the heat anticipator to 1.2 I will certainly get the best main vents that I can. I will look to order the Bigmouths tomorrow or Monday.

Thanks Again.

Jamie Hall

In a very real sense, @Hatterasguy is right -- the anticipator is a very poorly understood bit of a thermostat. And it's only on older thermostats -- most newer ones have a cycles per hour setting.

It's basically nothing but a very small electric heater nestled next to the bimetal, which causes the thermostat itself to warm up faster than the air around it. The heating element is powered when the thermostat is calling for heat. If all burner controls were the same, it wouldn't be such a hassle -- but they aren't. Nor are all heating systems. The only really sure way to properly set an anticipator is to observe the performance of the system as a whole, and adjust the thermostat to minimise the overshoot. On some systems, that may be all the way out at 1.2. On others, it may be much lower. As they say, your mileage may differ.

It is not there to control how often the thermostat calls for heat -- that will be determined by how fast the building is losing heat. Or should be. Nor is it there to control how often the boiler cycles on pressure, if at all. That is determined by how big the boiler is in relation to the radiation it is feeding, assuming your venting is even close to adequate.

Bottom line: set it so that your system doesn't overshoot much, if at all. And leave it there. If you are still having the boiler cycling on pressure, so be it. The anticipator isn't intended to fix that -- and won't.

TGALL

@Hatterasguy - thanks. Today I kept the air vent off the little radiator and set the heat anticipator back down to the sensitive setting .4 When the system called for heat. And the boiler had not run for several hours prior to this. It took 8 minutes for the heat hit the last section of that little radiator. I quickly got the vent on (almost burning my fingers). 8 minutes after that the thermostat was satisfied.

So, a whole heating cycle complete in 16 minutes. Moved the temperature from 73.5 to 75.0 ( I bought 2 different style digital thermometers and placed them on a shelf right next to thermostat). So, yes I keep my house warm. The thermostat is set to 71 but I had never measured the actual temperature before. So that is probably off due to not being level that @Fred mentioned.

I checked the other 11 radiators. 2 were not hot enough but the other 9 were hot for each section top and bottom, left to right.

Eventually I will get to insulate the basement pipe. And I will replace the main vents. But for now, I just want to find the fastest vent for that small radiator.

Thanks all.

TGALL

@Hatterasguy - thanks. Yes I was looking at the same on the internet yesterday.

Also, I called a furnace guy who will replace my 2 main vents Gorton #1 with Gorton #2(s). I checked and have 4 or 5 inches of clearance.

I also found 2 bigger radiators on Craigslist and will replace 2 of my smaller ones. This will give a slight help on EDR to Furnace match. Adding 20 EDR.

The furnace guy said he would not put a smaller nozzle in than specified. So, I am going to skip this for this winter.

Between the time I started this thread 3 or 4 days ago and now, I had to replace a radiator vent that would not close.

1 question... At the end of a heating cycle , is it normal for the radiator vents to make a lot of noise? Are these vents 2 way? meaning does air rush out when steam is coming (yes). And does air rush in when heating cycle complete? Something happens at the end of my heating cycle but I can't tell if air is coming out or going in. I have to put a feather next to it next time.

Thanks for all your help!

nicholas bonham-carter

Yes the air will rush back in through the radiator vents, and also through the main vents. This loud hissing is a confirmation that your main venting is not adequate, and is costing extra fuel dollars to push the system air out of the constipated little openings of the rad vents.
This is the cause of your short-cycling.--NBC

ChrisJ

EBEBRATT-Ed said:

Put the ,85 nozzle in and tweak the oil pressure up a bit.

We are getting blinders on our eyes about venting and adjusting pressure controls. I don't care how many vents you put on or how you adjust the pressure control.

IF THE BOILER OUTPUT EXCEEDS WHAT THE RADIATION AND PIPING WILL CONDENSE THE BOILER WILL BULD PRESSURE AND SHORT CYCLE NO MATTER HOW MANY VENTS YOU HAVE OR HOW MANY PRESSURE CONTROL ADJUSTMENTS YOU MAKE.

The trick is to tweak the boiler so the output matches the radiation load + a tad for piping and pickup and then fix the venting.

The boiler then will most likely never build pressure, you will save fuel, burner ware & tare, smoother operation, less noise lower stack temp, better efficiency and a more stable water line.

The burner sitting idle for only 2 min. is not good

This is what I keep saying but most keep ignoring me because there's no way the typical system loses 33% through 1" insulated piping.

nicholas bonham-carter

Yes an oversized boiler will still short cycle as the steam output exceeds the capacity of condensation of the rads, but with generous venting, at least steam will make it into the rads before the short cycling begins.
Short cycling during the venting phase will probably cause more discomfort and fuel use than during the condensation phase.--NBC

EBEBRATT-Ed

@ChrisJ , I agree

john walsh_2

Just curious, when you calculated the EDR of the system radiators, did you also add in the piping pickup factor of 30 percent? That's all the piping that connects the boiler to the radiators. If you didn't, then I would think that your boiler is sized just fine.

TGALL

@john walsh - no, I did not add 30 percent. From what I read you just add the radiators EDR and compare that to what is documented for the boiler and I thought the boiler documentation accounts for a .33 adjustment?

TGALL

The heat timer varivalve is due to arrive today. In the meantime, I put a hoffman 1A set to "fast" on the small radiator and have not short-cycled since. Heating Cycle is still a bit long for me (28-30 minutes). I would like to get this down to 20 minutes. The furnace guy that I called for the Main Vents has not called me back yet. I told him Gorton #2(s). If that Barnes and Jones Bigmouth becomes available I will just order 2 of those.

With the symptoms that I have and all the comments received, I am certain that upgrading the main vents is a good thing. And hope it will get me closer to the 20 minute goal. I probably won't need the heat-timer varivalve after the main vents are done.

Also... any comments on the note just above would be appreciated. Was I supposed to add 30 percent to my radiator EDR ? I don't think I was, but I am a novice at this.

And, I am picking up a bigger radiator on Saturday.

Thanks.

ChrisJ

Depends.

If you do like I do, and use the DOE output, you add your own pickup factor in whether it be 10%, 20% etc.

If you use the manufacturer's rating for sqft of EDR, the 33% is included in that. You do not add 33% on top of their EDR rating.


If you take your EDR and multiple it times 240 it'll give you the btu/h your radiators can dissipate. Compare this to the DOE output of your boiler.

TGALL

The first sentence of my thread was...

I have a Weil McLain SGO-4, which today discovered is oversized. My 12 radiators add up to 326 EDR. I calculated that I need 78,240 BTU / hr. The Weil McLain is rated for 108,000 BTU / hr. ( 450 sqft of steam) .

My 12 radiators add to 326 EDR. I took 326 x 240 = 78,240
The Weil McClain SGO-4 has 3 useful numbers ...
DOE Heating Capacity 144,000 BTU /hr
Steam Rating 108,000 BTU / hr
Produces 450 sq ft of steam

I did not add any pick up factor. I figured the difference between 144,000 and 108,000 accounted for normal piping (which I think I have).

Do I need to add a percentage to the 326 or therefore the 78,240 ?

TGALL

Sorry the Steam Rating is not in BTU/ hr . But it is 108,000.

ChrisJ

144,000 btu/h is the boiler's actual output without any piping or pickup factors.

108,000 btu/h is what they're claiming it can heat, radiation wise. This includes a deduction for alleged piping losses. If you multiple 108,000 times 1.33 you'll get 143,640, approximately the boiler's DOE output.


108,000 btu/h divided by 240 = 450 sqft of radiation, piping and pickup factor already included. Do not add anything.

Personally, I'd say it's good for 480-510 sqft if the piping is correct and insulated.

ChrisJ

Exactly as you thought, your boiler is quite a bit oversized.
It's capable of producing 144,000 btu/h worth of steam and your radiators can only consume 78,240 btu/h plus 5,000 - 15,000 for piping losses give or take.

Sailah

TGALL said:

If that Barnes and Jones Bigmouth becomes available I will just order 2 of those.

Big Mouths are done today and can ship from factory. I'll send to Amazon today as well but it will probably be a week for them to get into their system.

So best bet is to call me and I'll send from here.

Thanks

Peter

john walsh_2

Okay. I always use the DOE heating capacity and add in my piping pick up factor to the radiators. Your boiler is definitely oversized. Rapidly venting the mains and balanced venting at the radiators is great, but if it was my house/job, I would definitely consider getting a professional to reduce the nozzle one size. When you think about it, if each radiator is sized correctly to it's corresponding room, and vented properly, the same percentage of each should heat on a call from the thermostat. Only on the coldest days should the radiators heat all the way across, and only the coldest of the coldest should the boiler build pressure. An oversized boiler will make that nearly impossible.

TGALL

@John Walsh - I just need other opinion here because the way I understand it... If the mains are vented good, heat should hit all the radiators at the same time. And then each radiator is vented according to it's size (assuming radiators are sized correctly to the room they are supposed to heat).

It takes the radiator to be fully hot (all sections) for 6 to 8 minutes to satisfy my thermostat. All 11 of the other radiators are fully hot by the time this 6 to 8 minutes elapses. On any day, doesn't matter if it is a mild 50 degree day or a colder 25 degree day.

I don't set back my thermostat at all. Always set to the same temperature with the heat anticipator now set at .4

On a side note --- the heat-timer varivalve arrived yesterday. I put on set to fast setting and it has worked just as described. I hope it lasts. And if it does, I wonder why they are not recommended more by you professionals?

Thanks as always.

john walsh_2

@TGALL I admire how you've taken the time to study your system, and I totally understand wanting other opinions. Don't get me wrong, venting is extremely important for even heat distribution and it's good that you're taking the time. I'm just saying that your always better having the boiler output match the connected load. It will help produce dry steam at the boiler which saves fuel and with proper venting, you won't even hear a vent (except the click when it closes) which gives long life to them. It will still heat the rads, just slower, and that will help keep costs down too because on warmer days, it will be less likely to overshoot the thermostat setting. Just my two cents.

ChrisJ

john walsh said:

@TGALL I admire how you've taken the time to study your system, and I totally understand wanting other opinions. Don't get me wrong, venting is extremely important for even heat distribution and it's good that you're taking the time. I'm just saying that your always better having the boiler output match the connected load. It will help produce dry steam at the boiler which saves fuel and with proper venting, you won't even hear a vent (except the click when it closes) which gives long life to them. It will still heat the rads, just slower, and that will help keep costs down too because on warmer days, it will be less likely to overshoot the thermostat setting. Just my two cents.

John,

How much do you think a qualified person could downfire that SGO-4?

Would they be able to drop it down by 40K or even 50K?

If so, I'd definitely go that route too. Not only will it save oil, it's going to operate so much nicer and quieter. A bit slower on startup, but slow and steady wins the race in heating in my book.

TGALL

@john walsh - the reason I am currently focusing on venting and settings and radiator swap outs is because I can do these items myself. I called 2 professionals and asked about down-firing and both guys told me it can't be done. I know from reading here that it can be done, but I just can't find someone that has done it before. Yet... i have the 2 prior nozzles that my guy put in and they are both different size than the one that is in there now.

I have a 1.1 in there now. And, the 2 older ones are 1.0 and 1.25

The last guy that I called told me my pressure setting is too low. That I should up the pressure to avoid short cycling. I almost don't want anyone touching my system because I feel they just fix something and then wait for the next thing to break and fix that. nothing malicious... just not the care to have it running as best as possible.

Thanks again.

john walsh_2

@ChrisJ , I wouldn't down size more than 15 percent of the input BTU rating, you definitely don't want to downsize too much, that can cause it's own problems including high fuel bills. Since I'm not an expert on nozzle replacement, I will defer to other more knowledgeable guys on this thread.