Boiler Still Shutting Off

michael_15

From an amateur.

When it turns off, are all the radiators heated all of the way across? If so, how long does it take to turn back on and how long is that subsequent cycle?

A typical boiler, if there is a lot of heating needed, will shut off on pressure before satisfying the T-stat but after all of the radiators are full of steam. That should be OK, but it should turn back on again once the pressure drops.

Do you know the GPH setting and the EDR of your system?

I don't believe you can realistically have too many main vents on a parallel-flow system. I suppose in theory (though highly unlikely) you could overvent a counterflow system.

-Michael

John Van Hoesen

Oversized Boiler?

Hi all -

Still having issues with my boiler shutting off after running for 20-25 minutes, so it isn't short cycling, but it also isn't satisfying the thermostat.

My pressuretrol (see two attached images) is set for 0.5 psi with a 1.0 differential. That's what I've read is correct so that's what I've set it for. However, I believe there is too much pressure building up in the system prior to satisfying the tstat.

I have a 1400sf house, and a total of 8 radiators (7 on the first floor and 1 in the upstairs bathroom). The boiler is a Burnham V86 and Becket Burner. I'm starting to wonder if it's too much boiler for this little house and if so what can I do to decrease the pressure so the thermostat actually gets satisified. Or am I missing something else all together?

Can't figure this out, I've been dinking around with it for awhile now and the 'cold' is coming now so I want to alleviate this issue. Any other thoughts or suggestions would be greatly appreciated! Thanks so much.

One last thought, could I need to add another Gorton #2 to the end of each main? I currently have two there, would another help alleviate the pressure or just be excess? Can you have too many main vents?

cheers
John

Empire_2

Just a thought.

T-Stat... Make sure the anticipator is maxed out for there is no anticipation on boilers. This only applies if you have a t-87 or simmilar. Also try setting the diff to 2.

Dale

Shut off

I would try to figure out what is shutting the burner off. It could be any of the switches in the power chain. Most likely the stat or pressurtrol of course. If the stat then the aticipation post is correct, if the pressure switch what is it really seeing for pressure, is the pig tail partially plugged? I would do an edr for the rads and find out what the boiler is rated for, perhaps the boiler can be fired at a lesser rate. Is the boiler clean? When was it skimmed? As the other post said are all the rads hot all the way accross? You can safely check the stat by jumping it out when you're there to see if the boiler keeps firing. And, you can use a clear tubing run to the ceiling from the drain to check pressure, 28 inches equals on pound.

John Van Hoesen

Rads...

Yes, the radiators do heat all the way across and they boiler doesn't come back on for some time. I assume that the steam pressure would drop off rather quickly and then the boiler would come back on to satisfy the tstat, but it doesn't. I cranked my tstat up to 75 but it shut off at 70 and then climbed up to 72 with the remaining heat radiated by the rads. BUT, it didn't kick back on after the steam pressure dropped.

No, the pigtail isn't plugged, I pulled it out and checked. I'm pretty sure the GPH is 0.8, not sure on the EDR. Easiest way to find out? It seems really weird, the only two possibilities are the tstat and the pressuretrol and both seem to be working they way they are supposed, but in combo they aren't working properly.

This is the tstat I put in:
http://www.homedepot.com/prel80/HDUS/EN_US/diy_main/pg_diy.jsp?CNTTYPE=PROD_META&CNTKEY=SuperFeatures2/Miscellaneous/PM_Affiliate_Landing_Page_2005&cm_ven=hd_goog&cm_cat=Search1&cm_pla=D-Brand&cm_ite=bid10130339-home_depot

It's nothing fancy and I don't believe it has an anticipation setting, didn't see any in the instructions, but I'll check again. Either way, if the anticipation set too low, then when the tstat wasn't satisifed, the boiler should come back on to bring it up to temp right?

The boiler block was replaced this summer, so its got a little crap to clean out, but I've been flushing regularly like I'm supposed to the first few weeks.

If I set the diff to 2, will that allow MORE pressure to build up in the system? Resulting in MORE fuel consumption?

This seems like a really stupid problem that should be easy to fix but I can't figure it out... Thanks again for all your commments, a few more days of tinkering and I'll call in a professional.

cheers
j~

thfurnitureguy_4

John, remember that your Sq. ft of radiators and the Net I=B=R rating of your boiler should be about the same. There are charts available on the net to find out the EDR of each of your radiators. You need to know the # of sections, the type (1,2,3 etc.,tube or column), also the height of each of the radiators. Next,you just add up the EDR and compair to the I=B=R net rating Stamped on your boiler. If its like alot of them it will be oversized. Some solutions if it is: Down fire your boiler (a little)By using a smaller oil nozzle. If down sized to excess you will cause a host of other problems. Another solution, if over sized, is to add radiation (more radiators or larger ones) Any cold spots in the house? A third is to add an indirect hot water heater. If your boiler will accept one. there is a section on this site called contact a professional. This could save you alot of money in the long run. Finally Is your house warm? Anything you do will cost you money. Is it bad enough to require spending the money? Be sure to find out what the manufacturer calls for with a burner setup before you start changing things. If the system is way over sized they may have down fired it all ready. Your owners manual will tell the desired setup for the burner find out what you have now before you start swapping and changing. Burnham has the OM on Pdf on there site. Good luck and call the pros.

Steamhead (in transit)

John, that link didn't work right

is this a programmable thermostat? If so, check the instructions- there should be a way to change the number of cycles per hour. Most come set to 6 CPH- try resetting to 3, and if that doesn't cure the problem and you know it's not shutting off on pressure- set it to 1.

John Van Hoesen

Thanks Steamhead...

Here's a link that will work: http://www.ritetemp-thermostats.com/8022.html

It is a programmable thermostat, I'll check the cyles. Does the idea of another vent make sense? I have two Gorton's (as you suggested) on the end of each main now, I could add a third? Would that adversley affect anything? Is extra venting bad on mains like it is on rads? Thanks!!!!!

cheers
John

Al Gregory

That boiler is big enough to heat a small church. If the rads are hot all the way accross when it shuts off its just going off with presure. Ask your tech to downfire it a little. Longer run times are better for the boiler.

John Van Hoesen

Yeah

It seems big to me too... I'll call them in and ask them to 'turn it down a notch' if I can't make sense of it in the next few days.

Thanks!
J~

Henry C

You say you have a 1400 sq ft house with 8 rads. I can only guess at the exact EDR, but my gut feeling is that boiler is way too big for your house. That is a 6 section boiler and you probably could have gotten by with a 3 or 4 section model. Just a hunch. How did they size that? Why did they go with that model?

John Van Hoesen

Burnham V8

It's only a 4 section boiler... not 6 section, but still seems big... Thanks!

J~

Mike Cascio

Hi,
You mentioned that you have 7 radiators on the first floor and one one the second floor bathroom. What is the rest of the second floor heated with?

John Van Hoesen

Rising Heat!

There are two grates, each over a radiator on the first floor and rising air heats the two bedrooms. Haven't spent a winter here yet, so I don't know how it will work yet...

I'll keep you posted! ha ha..

J~

Unknown

Unknown

John

I bet even the 4 section Burnham is oversized for the amount of radiators you have . You can do the EDR with the Burnham Heating Helper , which they have online at their website . You may be able to downfire the burner to get closer to the actual load of the home .

It looks like they reused the old pressuretrol ? I would upgrade it to a newer model with a new pigtail . We use the mercury controlled brand , but I'm not sure if they're still being sold .

Do you have any pics of the boiler piping ?

John Van Hoesen

Pics

Hi Ron -

Here are some pics... "They" is me... I replaced the boiler block (I used everything else that was on the boiler because it was only installed 2 years ago, they froze the house and cracked the back section).

I'm in the midst of re-insulating the pipes, just installed those gortons and need to clean and skim the boiler (this weekend actually). Anything you see that looks wrong (other than not having a nice drop header) would be appreciated. But yes, I think it's too big. Think I might decrease the nozzle to see what happens.

Thanks
John

Alan_11

what's the problem

At the price of fuel oil today ,the longer thge burner is off , the less oil you burn. Stop guessing why the burner is off and diagnose the problem. If your capable of replacing the block yourself , you should be able to use a electrical tester to see why the burner is off. Or next time it shuts off try jumping out the thermostat terminals on the primary control to see if the burner starts,or raise the pressuretrol setting to see if it starts. Glad to see somone used sheilded oil line on the job,required in Mass,maybe not where ron jr. works.(that j-box on the front is a nice spot for sevice switch ,with thermal switch at ceiling---temporary wiring?

Rely_2

pressuretrol

try raising pressuretrol just a little bit you may have it to far down it may read .5 but it can be lower.

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Unknown

Not sure

why we put the service switch at the celing . It might have been because the basement lights were hooked into the boiler circuit , and we didn't want to shut it off again . No code for a thermal switch or coated oil lines . Some inspectors want the line covered with cement though .

Ease up on the 'tude , Alan . Replacing the boiler block and knowing how to diagnose wiring problems is 2 different animals .

John Van Hoesen

I did...

I did test the tstat vs the pressuretrol. As I stated in one of my previous posts, if I go down and turn the screw up higher the boiler will come back on (but only until the pressure builds up again). So the questions is still why the extra pressure. 4 total main vents (gorton 1) and all new radiator valves.

I rant the coated line through pipe under the basement gravel floor just to be safe, installed all new firematics, and the thermal cut off swith is directly above the boiler on the ceiling. The service switch is located at the top of the basement stairs (there wire runs up to an electrical box that then goes to the service switch at the top of the stairs AND the electric box is 2 ft away from the boiler with a clearly marked Furnace breaker) and I'm planning on installing 2 sprinkler heads over the boiler in addition to the firematics and thermal switch. Not sure what I did wrong there...

Thanks!
j~

Unknown

He was referring

to the pic of my install , John . In a previous post you said you set the thermostat to 75 and the boiler shut down at 70 . Was it shut down on pressure ? Is the boiler pressure gage accurate ? The PA404 is not the most accurate pressuretrol on the market . We had a run of bad ones a few years ago - we set them exactly like you did . They would cycle once and not come on again , or not cycle at all unless you set the cut in around 5 psi . It's why we switched to the mercury controlled version .

John Van Hoesen

Oh!

Thought it was my pic. So what would you recommend replacing the PA404 with? What model number? Can I keep the Honeywell control, or do I have to replace that too?

Thanks!

J!