short cycling steam boiler

Al Corelli

What's an IPM?

Joe_68

short cycling steam boiler

I had a new Utica steam boiler installed to replace an old oil fired one. IT is short cycling and no one (plumber,electrician) can seem to find out why. When the thermostat calls for heat it runs for about 3/4 minutes and stops. The water in the gauge isn't surging so they ruled that out. They changes the thermo. about 3 times and no change.They then said it was the IPM and after waiting 1 week for the part to come from Utica they changed it. Unfortunately that didn't solve the problem and it still behaves the same.

The strange thing is that even when you bypass the thermo. and wire it directly to the 24v transformer it still short cycles, but works a little longer, about 5 minutes before shutting off. What could be causing this? Both the plumber and the electrician seemed to be stumped.

Anyone have any ideas?
Thx

[Deleted User]

If the thermostat

has a heat anticipator, set it to .6A or higher. If it is an electronic, set it for 1 cycle per hour.

Joe_68

honeywell round

thermostat anticipator is set to 0.90 as per the installation manual of manufacturer. Correct me if I'm wrong but if I bypassed the thermostat and wired it direcly to the transformer. Shouldn't it have worked until I manually shut it off and not turned of by itself and in such a short period of time (about 5 minutes)? This is driving me nuts since it's not working long enough for the heat to reach the radiators in the front lower and upper floor of the house.

ttekushan

pressuretrol

Check to make sure the pressuretrol is set correctly, say 1 lb cut-to be sure its functioning.

Now make sure that the pressuretrol is LEVEL 'cuz they usually have a mercury switch in them. make sure the pigtail on the pressuretrol is set up so that heating and expansion can't move the control side to side. Set it up so that it moves towards and away from you as you look at it straight on.
Fore-aft, up-down. Doesn't matter. Side-to-side, trouble.

Also don't forget that proper air venting may be a problem since the new clean fresh boiler is probably developing a lot more steam volume than an old crusty boiler of the same output.

These are merely other ideas you might consider as you are at the point of grasping straws and banging head against the wall.

Mitch_6

Try switching the motorized vent damper to manual if you have one, you could also try jumping out one safety at a time and watch the boiler this will at least eliminate some suspected items. What type of ignition system do you have you could also try to rule out a flame recognition problem.

Mad Dog_2

Are you sure

its clean? Did you flush skim? A dirty probe on the lwco can cause this scenario too. Pull the probe, clean it up nice and try to run it again. Then clean the hell out of the system again. Mad Dog

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

thfurnitureguy_4

Is it shutting off on pressure?

thfurnitureguy_4

Things that will shut off your boiler after 5 min. T-stat, Pressuretrol, low water cutoff, Do you have to press the reset? Start disableing controls (while you are there)and see which one is bad. Is your water leavel staying up? you may have a plugged return.

Joe_68

It's the dang IPM

or so it looks like it.

I put the Tstat at 80 and turned on the boiler at the emergency shut-off swith. She fired up on que. I then took my newely bought multimeter and started checking currents. Their was 120vac flowing throught the Pressuretrol and the LWCO. The transformer and tsta both read 25.6vac. The gas valve, as expected, was getting the 24vac it needed to be open.
The boiler worked for about 5mins. and the stopped. I rechecked for current flow. The Pressuretrol and the LWCO were still letting 120vac current flow, so I figure they are workibg fine. The transformer was still letting current flow only now it read 27.1vac. I figure this is because there was no load since the boiler shut down. The tstat was still reading current so It was still calling heat. The connections at the IPM were also ready current. but the gas valve was reading 0vac it wasn't getting the 24vac it needed to open.

Could it be that the IPM is malfuntioining? It is a UTEC 1003-620A and is less than 3 weeks old. Have these models been prone to malfuntioning problems? Are these a good brand IPM or is Honeywell better? Which honeywell IPM would be compatible to this UTEC model?

Thx all for replying and HAPPY THANKSGIVING to you and yours

Steamhead (in transit)

Intermittent Pilot Module

the Honeywell S8610 unit is probably the one we see most.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Dave_22

Your pressuretrol and LWCO only have to flicker for a split second to shut your system down. Unless you have a Fluke 87 or such meter that can record high and low and hold it, I would be skeptical of what you are seeing.

Joe_64

I tried it again

and this time to be sure that their was absolutely no doubt about the IPM I left the probes of the multimeter on the transformer through the whole cycle and kept an eagles eye on it. Since the pressuretrol and lwco are connected to the transformer. If they were to cut off current I would get a reading of this on the multimeter.

Well the boiler did the same thing as before and the only difference in the reading the multimeter gave was 25.6vac during cycle and 27.1vac after shut-off. Nowhere in betweeen was there a low reading from the multimeter sugesting that the pressuretrol or lwco had tripped.

Any other ideas? I'm beginning to think that this boiler hates me. LOL.

Thx for the replies.

Dave_22

I would bypass the pressuretrol and LWCO-one at a time, while standing close by with a hand on the power switch and make SURE your not barking up the wrong tree!!!

Rodney Summers

Flame roll out

Check your flame roll out switch. I had one do that it had me ready to pull my hair out. As suggested you need to jumper out one thing at a time till you find the cause. Also check all the factory connections you may have one that is loose and becomes to resistive and lets the unit drop out.

David Nadle

What model Utica?

Joe, I have a Utica PEG-C, and on that model the pressuretrol and LWCO are part of the 24V circuit. You can't measure the voltage "through" something, only across it. I wonder how you measured the current. The boiler is one big series circuit so knowing the current won't tell you which component is breaking contact.

On the PEG there is also a rollout switch, a blocked vent switch, and a spill switch. I would look at those.

JAMES MEDINA

short cycle

is the pig tail plugged up with crud?

steveex

Jump out each control seperatly, ie tstat, prestrol, lwco, roll out and spill. Each one for 10 min. If nothing spark pack malf. or gv

mark_121

Try this

to see if it is the IPM gust shut the main gas valve off and let it think it is running wait and see do not let it go to main flame.