Weil-McLain EG-40 intermittent startup with ongoing start signal from thermostat

cantab · February 21

Hi everyone, Over the last six weeks or so the WM EG-40 boiler (one-pipe steam) is intermittent in starting the heating cycle, even while the thermostat is continuously calling for heat. Seems to be failing more frequently and last 24 hours nearly continuously, see graph log below for past 24 hour and past 3 days.

Boiler was installed in ~2004 and has run well since I purchased the condo in 2020. The boiler is serviced annually/regularly. Several plumbers have indicated the installation is good. Pressure seems fine. Water level is fine; manual feed. Thermostat, Ecobee, seems fine. Installed in an open space, so should be getting plenty of air.

The boiler was serviced recently and twice by two different companies without a fix and annual maintenance indicated no major issues... However, there is definitely an issue.

Ecobee was on boiler 24v supply without issues. Now on dedicated 24v supply per recommendation. The new voltage supply did not result in a change in state of problem. So that seems an unlikely cause.

Pig tail was clogged according to second service call and was replaced (no explanation for why replaced vs cleaned).

Seeking reputable service provider and steam boiler troubleshooter who makes calls in the Boston area. Unfortunately the experience so far has been of questionable information from generalist HVAC companies and qestionable and different suggestions for repairs, e.g. over $2500 without data based reasoning, on several occasions. Vendor names withheld as I'm seeking recommendations for service providers rather than to leave a bad review.

So far, I am over $1000 dollars into seeking a solution for the intermittent boiler startup without a fix and over 60 hours of time my time for online boiler research, phone calls to service vendors and Weil-McLain (who have been good even though they don't take calls from the end-user), calls and communication to vendors, reviewing thermostat logs, calls with Ecobee tech support, and etc.

Please suggest vendors you like and trust so we can get our heat back on consistently.

Thank you.

mattmia2 · February 21

@New England SteamWorks ?

mattmia2 · February 21

so when it won't fire, what happens if you jumper t-t or r-w or whatever the heat thermostat contacts are called on that boiler, sometimes they are r-g if it is using a fan center for isolation. normally a clogged pigtail will cause it to not shut down on pressure, not keep it from firing.

mattmia2 · February 21

I don't think @Charlie from wmass works in boston but he is excellent too.

Charlie from wmass · February 21

See if the light is coming on at the low water cutoff. It is likely due a new probe. The other issue could be a problem with the micro switch in the damper.

cantab · February 22

Thank you for the suggestions. I will follow up on those that I'm comfortable doing myself.

I'll reach out to Charlie from Garrity tomorrow and/or Monday, they are in Springfield which is pretty far (for Massachusetts distances) so I might be outside their area.

Supposedly the probe was cleaned during the annual maintenance earlier this week. Seems I'll have to double check that.

The interesting (and frustrating part) is the intermittent nature, however today it seems to be mostly failed and a lot less intermittent.

cantab · February 22

Still seeking suggestions for Boston service area steam men and women to come onsite and help tame the dragon back to its usual placid behavior.

EBEBRATT-Ed · February 22

There are about 4 controls that will prevent the boiler from TRYING to start.

Thermostat

Low water cutoff

Pressure control

Damper end switch

Try to find which one it is and just as important eliminate the ones that are easy to check.

I would suggest

Try another thermostat

Check for loose wiring including at boiler connector plugs and anywhere in the system

Make a list at what you have checked and cross them off when sure they are ok

Low water cutoff you can probably trust the status lights

Pressure control. Make sure piping and pigtail is clean. Make sure the cutin is not set so low the boiler may not start. You could raise the cut in temporally. Count the turns you raise the cut in screw so you can later return it to the proper setting if its not the issue.

Don't focus so much on finding the problem. Eliminate things and the problem will show up'

Unfortunately good service techs are rare now. You have to take matters into your own hands

109A_5 · February 22

The Universal Spark Ignition Control can be intermittent, and the flame detection too.

The control supplement documentation may help.

https://www.weil-mclain.com/sites/default/files/field-file/eg-peg-egh-control-supplement-manual_1.pdf

Here is one example from the document there may be another that is closer to your unit.

HVACNUT · February 22

https://forum.heatinghelp.com/discussion/comment/1844227#Comment_1844227

There's a little switch on the vent damper motor (auto/manual). The next time the damper is open and the burners fire, switch it to manual and see if the issue dissappears. If it does, you can leave it that way. I think it'll cost a 2% drop in efficiency.

Weil-McLain EG-40 intermittent startup with ongoing start signal from thermostat

Comments

Categories