boiler cycles too much

phil the limey

yuk, id hate to have to swap out the tank, they cost about 1200 bucks, maybe ill put a water heater blanket wrap thingy on it.

i dont have a recirculater on the hot water.

i was just hoping for a way to heat it up way high, then have it wait until it was really needing heat before it called for it.

phil the limey

boiler cycles too much

i have a burnham boiler, with an amtrol 42 gal tank (with a coil inside) and basic white-rogers non-digital stats.
boiler is on at 3am, 4am, 5am......all at times when there is no hot water drawn. how can i set the limits differently? not sure what technical terms i should be using, but i need to set the tank so it calls for heat until it reaches one temp, but does not call again until it is a lower temp.
like a differential i guess you would say.
ps i installed the system myself, have had no problems with it, and i just noticed this. i should say i have no clue what the anticipator does, and have never tinkered with it. could that be it?

Ron Schroeder

What are the settings on your Amtrol and boiler now? And what is the model number of the Amtrol aquastat and the boiler aquastat?

phil the limey

boiler is at 145, amtrol is at 120. i looked at the aquastats, but couldnt see any model numbers. would pictures help?

lee_7

pictures always help.

Ron Schroeder

The boiler aquastat most likely has 3 settings, Hi Limit, Low Limit and Differential.

What are those settings?

phil the limey

well ill have to go and get another look. the thing i saw that i thought was the aquastat had a steel stamped wheel, with almost a toothed edge (for turning grip i assume), and stamped in numbers up to 180 and a small pointer to get a reading from.

phil the limey

heres a pic of the aquastat in the boiler, on the amtrol and amtrol with panel removed

phil the limey

Jack P.

The first pic is the aquastat, the second pic is the tank temp control and the third has me a little puzzled. It looks like a temperature probe of some sort. Why it is out in the open is puzzling also.

The aquastat is holding the boiler temp at 145 when you are holding the tank temp at 120. There is no reason to hold the boiler at 145 unless you need the tank to recover quickly when and after water is drawn off the tank. I would lower the aquastat to 120 or just a little above that. When you start into the heating leave it at the 120 until that temperature will not keep up with what your thermostat setting is. Then raise the aquastat temp about 20 degrees. There is no reason to over fire the boiler temp if the circulator will keep up with calling temp. As the outside temps fall over time keep raising the aquastat temp 20 again to meet the calling temp. There is no reason to run the aquastat at 180 if it is not needed. In the spring as outside temps warm up do the reverse. That way you are getting the best efficiency and the best bang for your buck.

Ron Schroeder

The boiler aquastat is somewhat different than what is usually used on a boiler. Single aquastats like that are usually used on water tanks. Sometimes boilers are controlled by several single aquastats like that one instead of the more common triple aquastat. Have you checked the boiler to see if there is another aquastat someplace in another tapping or straped to the supply pipe?

phil the limey

the probe out in the open is simply an extra aquastat i have laying around. thought you might like to see the rear of it without dismantling the one on the tank.

there is no other aquastat on the boiler, what you see is what you get.

what is a good temp for domestic water? (as in the amtrol setting)

Glenn Harrison_2

Gas fired Boiler

Ron, that is a gas fired Burnham, I recognize the set up in the pick.

I haven't seen a gas fired boiler made in the last twenty years with a triple aquastat on it.

Glenn Harrison_2

I would be willing to bet...

that what you are seeing is normal for your setup. Most likely, you are loosing enough heat out of that Amtrol just sitting there to cause the Amtrol temp control to kick on and then the boiler fires up until the Amtrol is satisfied.

Solution: Replace the Amtrol with a newer Indirect tank that has better insulation package to keep the heat in the tank. Another thing you could do is install a timer in series with the Amtrol control that would prevent the Amtrol from calling during night hours of your choice.

One question, do you have a hot water recirculation loop hooked up to the Amtrol. If so, this is adding to your problem. If you have a recirc loop with a pump (usually the case),the pump should be put on a timer that turns it off at night when not using hot water.

lee_7

i have same type of aquastat on my crown cold start boiler

phil the limey

what kind of timer would that be?

Ron Schroeder

Hi Glenn,

I have only worked on one gas boiler and it has a L8124E on it. I mostly work on oil or heat pumps.

Ron Schroeder

Hi Phil,

If you want the Amtrol to get hotter and not call for heat untill it cools down more, you need a wider differential on the Amtrol aquastat. The aquastat that is already there may or may not have an adjustable differential. Often the indirects differential is 5 degrees. If yours is adjustable, setting it to a wider differential will reduce the number of boiler cycles.

On my indirect, I am running a 40 degree differential and in the summer I only get one boiler cycle per day or less. I have a cold start boiler. I had to replace my indirect aquastat with a new one because the original had a fixed differential.

I also have a tempering valve on the DHW out since the tank can get so hot.

The tank blanket will also reduce boiler cycles but not as much as a wider differential.

heatguy

call amitrol

i noticed you happen to have extra aquastat laying around if the aquastat was changed it is important that it sits at proper spot in tank and you can also change cycle by location of aqua bulb call amitrol.it also sounds like your high limit may be set too close to your stored water temp all else fails do the timer on second thought do timer anyway

Unknown

Your setup

What you have there is either a Burnham 2PV or SP series induced draft Gas boiler which is equipped with an L4080 Cold Start aquastat. That means that the boiler will only fire when a call for heat or Indirect is encountered. I can't see the setting on the boiler aquastat from your picture but if the pointer is pointing to 145°F as you say it is, that is far too low. That will need to be set to 180°F or so to keep your boiler safe from possible flue gas condensation.

The other result of this would be extremely short boiler burn cycles and lots of them to satisfy the Indirect or zones of heat. That many extra short cycles not only waste energy but will cut the life of the electronic controls and induced draft fan drastically.

The Amtrol aquastat shown in the last picture is only as accurate in diffential as its insertion in the tank. They normally have a small kink like bend in the capillary tube which is the indicator of how far up into the tank it should be inserted. The nut should not be able to go past that bend. The lower in the tank that aquastat bulb is inserted, the quicker it will cool down as cold water infiltrates in around it. If you don't see the bend indicator, cunsult with Amtrol and their customer service people will be able to give you an approximate dimension for insertion depth. Their number here in RI is (401)884-6300.

Ge that boiler temperature up, appreciate the longer running cycles and enjoy the better Indirect recovery you will get. It's darn tough to make Indirect Heater temperatures od 130-140°F when you are trying to do it with 145°F boiler water! Hope this helps.



Glenn Stanton

Manager of Technical Development

Burnham Hydronics

U.S. Boiler Co., Inc.

phil the limey

ok i checked the bulb depth inside the amtrol, its all the way to the top, so thats not it.
im having trouble comprehending why to turn the boiler up to 180, if the amtrol is calling for heat, its gonna call for heat no matter what the boiler wants to do, right?? so how would that reduce the number of cycles?
just couldnt see the advantage. maybe someone could explain in carpenter terms (kidding)

also, the adjustable aquastat seems a very valid idea. anybody tell me what to ask for? (what model etc) do i have to get it from amtrol? or would a generic one work?

Jed_2

Hot water supply pipe

How is that piped/ Where does it go from the top of the tank? Does it have a thermal trap? Is the Hot wter pipe insulated. Temperature migration to the faster cooling hot water supply line could be drawing off temperature, thus lowering the tank temp quicker, thus calling for tank recovery more often; an enrgy drain.

Jed

Unknown

Phil

In reading your post again, you say the boiler is turning on every hour for no apparent reason. That can't happen unless something is telling it to operate. One more thought regarding this would involve why the Indirect may be cycling on during the night. Do you have anything happening in the house that would allow hot water to leave the tank? This could be a slight drip of a faucet, a shower valve with hand shower mixer/diverter or even mixing valves on your toilets to keep them from sweating. If you have toilet mixing valves, they blend warm water with the cold going to the toilets. Eventually the internal check valves stick open and you end up with a cross connection from hot to cold.

Had a homeowner in NH complain of their SuperStor cycling the boiler on all of the time when they were not using hot water. Went to the job and found 3 toilet mixing valves of which 2 were leaking by. Add to that a plush green lawn that gets automatically sprinkled every morning and you have a lawn with warm water keeping it green! I'd focus on why that tank is turning the boiler on or where the hot water is going that is supposed to remain in the tank.

As far as the boiler aquastat setting is concerned, sure it will still turn on if something tells it to, but it is intended to operate longer burn cycles and needs to be hot enough while operating to keep flue gas condensation from ocurring. In addition, when you need to recover the Indirect when you take a shower, it will take almost twice as long to satisfy it with 145°F water as it will with 180°F and with drasticly short burn cycles to boot!

Glenn Stanton

Manager of Technical Development

Burnham Hydronics

U.S. Boiler Co., Inc.

Joe Brix

Maybe the Amatrol

is lacking a flow check or thermal trap? The hot water might be migrating up the DHW piping or the hot boiler water is backtracking to the boiler and taking the BTU's with it.

phil the limey

truly appreciate all the intelligent people helping out the strange limey dude. very much appreciated.

i dont have a single leak, im real picky about stuff like that. and i actually never heard of a toilet mixing valve, and i dont have any. (i know because i built my house myself, every nail, screw, shingle, concrete form, i even turned my own stair spindles blah blah blah) you can probably tell i am my own hero

i dont have much of a thermal trap on the outlet of the amtrol. attached picture #0758 shows the top of the tank, due to simple ergonomics, the hot does make a turn downwards for about 6" is that enough to prevent migration, or should i increase it?

the real reason im so concerned about the waste is because im pretty much cheap. im a cop and they dont exactly overpay us.

heres the rest of the story. below the amtrol tank you saw in the prior photos, is another amtrol tank fed by a solar loop. it enfuriates me when the solar tank has 180 degree water in it, (it feeds into the upper tank to pre-heat it) and the stinkin boiler is burning gas for no reason.

i guess ill put a blanket on the tank, a thermal trap on the outlet, and an adjustable aquastat on the amtrol, and hope that fixes it. i have attached pictures of my handiwork for all to admire.
now, can someone tell me what to order as far as the adjustable aquastat goes?

gilligan

bad amtrol?

I've seen a few Amtrol Boilermates where the internal plastic tank cracked, flooded the insulation and turned the tank into a radiator...is the tank hot to the touch? If it is this is your answer....

phil the limey

it is pretty warm to the touch, but nothing leaks. ive seen them do that too, but eventually it leaks out the bottom, right?

Gearhed

Aquastat settings

Phil,

Hey Bro... you gotta turn that boiler aquastat up. Like that Burnham guy said, it's far too low. You have a boiler that was designed to run at 180 degrees, and it's not going to perform at 140F. It cycles often because then 'stat is set so low that the hottest temp it makes is 140, and that just barely make hot water. I'm guessing you don't use much hot water, but if you did, you'd probably run out real quick with the boiler set so low.
The most effecient heat transfer occurs where there is a large difference in temperatures...ie 180 boiler water hitting the cold water in your boilermate. Unless it is leaking on the basement floor, you're wasting you $ by changing it out.
Also, read you boiler manual. All iron boilers have to run at 180, otherwise they short-cycle (which burns lots of fuel and wears out fans and relay's prematurley) and they condense (that condensation rots the iron out way too soon). Your boiler will actually run more effeciently at 180 than where it is now - and it will last exponentially longer.
No offence here, but the boiler isn't set up right. Listen to the pro's. This Stanton guy is an expert, he does all the Burnham schools all ever the country. Set the stat to 180 before you spend a dime elsewhere in the system and you'll see your problems are over.
Sounds like you did a heck of job building you own pad from top to bottom, congrats on the achievement. Now crank that 'stat to 180F and go get bad guys!

phil the limey

point taken. 180 it is. i know i need to listen better, but there are so many differing opinions, its hard to tell which is right. having said that, its only common sense that the burnham guy (thank you) knows his stuff. so ill start paying attention.

SO... after i switch it to 180.....what do i ask for as far as the adjustable aquastat goes? is there a brand name...generic...amtrol produced or what?

and do i need to increase the size of the thermal break above my tank?

thanks again.