Contactor/Relay on Boiler cycling and making noise

[BillTheEngineer]

I have a High-ranch style of home, 3 heating zones, with fin and tube baseboard convectors. The boiling is a early nineties gas files 2 stage boiler (Raypak H3-0125B).

Recently I have been hearing one of the contactors making a bit of noise (Not sure which one, there are 4, one for each zone and one for the boiler control). It seems to be cycling really fast (multiple times a second). I had this issue before and it seemed to be linked to the original mercury thermostats. I have replace all the thermostats with electronic ones. Once replace the problem went away. But the noise seems to have returned.

So I am thinking it's the contactor that controls the hot surface ignition that is making the noise. Is this a sign that the temperature switches, ignition module, probe, fast response temperature sensor or something else is on its way out? Is there a way to tell diagnose which component it is other than replacing each on a trial and error?

My first winter in the home I had issues with the boiler making a groaning noise with seemed to be an issue that it was heating water faster than it could circulate it and causing boiling. I addressed this by disabling the second stage on the boiler. Since then the groaning has gone away and there has been no issues. I guess this also goes to show how oversized the boiler is if can heat sufficiently even on one stage.

There is another circulator out of view behind the water heater.

 

[Leon82]

You can try to clean the contacts.

 

[Sponsor]

 

[Leon82]

but something like a 504 switching relay would clean that up

 

[DonL]

So I am thinking it's the contactor that controls the hot surface ignition that is making the noise. Is this a sign that the temperature switches, ignition module, probe, fast response temperature sensor or something else is on its way out? Is there a way to tell diagnose which component it is other than replacing each on a trial and error?

It kind of looks like the blue cap on the pc board has a leak, It is hard to tell from here ? I would move the wires farther away from the pc board components.

You can measure the resistance of the igniter to tell if it is cracked, It could be opening and closing when it heats up.

Good Luck.

 

[BillTheEngineer]

I have thought about putting in a 504. Once the stand alone water heater dies, I plan on putting in an indirect hot water heater.

It seems to be happening less frequently now and I stops by the time I can get to it. I'll look into the igniter.