[rlxyz0]

I have a Utica Gas Boiler, Model number MCB125HD, with 3 zone heat. below picture shows the settings

I found yesterday that there was no heat at home. After checking, I found the boiler making humming sound,
the Taco Circulator pump is hot but touchable. All 3 zone pipes were cold. The Circulator pump was replaced and about one year old.

I turned down the temperatures on all 3 thermostats and waited some time (maybe 45-60 mins).
The Circulator pump is also cold by now. I then turned up the temperature in one zone to above room temperature,
and the boiler fired up and the pipe warmed up. I then turned on the temperatures for all other zones, everything
seemed back to normal, the boiler back to work and rooms warmed up.

This situation has happened a couple of times recently. Anyone knows what might be wrong? Thanks for any help in advance

 

[jmon]

Circulator pump may be seizing up or getting ready to fail. It may have freed itself up and running again. Keep an eye on it.

If the pump is getting really hot, making noise or humming, and returns lines are cold,, it may need replacing/servicing.

 

[SW Dweller]

Time to learn the control system and all of its parts.
The concept of turning down the temps on the Tstats may be a simple rest for the controls.
When you came home the pump was running and all the valves were closed.

This is way to complicated to do by remote control. You need someone to look at and test all of the valves and controls.

 

[rlxyz0]

Thanks Jmon. Forgot to mention the Circulator pump was replaced about a year ago. How long the pump can last?

 

[jmon]

Thanks Jmon. Forgot to mention the Circulator pump was replaced about a year ago. How long the pump can last?

Well, cross that out then. Can't imagine it would go bad in a year. They can last 10-12 years, especially those taco's.

 

[jmon]

Post a better close up picture so we can see all the valves, switches etc.

 

[Matt1963]

I wonder if it was air locked. How many pounds is your system holding right now?

 

[rlxyz0]

Post a better close up picture so we can see all the valves, switches etc.

here are some pictures. Thank you very much for your time and help.

(1) the Honeywell valve was less than 1 year old, the middle one was about 3 years old,
the right one was there since we bought the house

(2) the blower motor is old and was there since we moved into the house

(3) here is the control and pressure gauge

(4) circulation pump and release value (both were replaced together about a year ago)

(5) Expansion tank

 

[beenthere]

Just a FYI. What your calling a blower motor. Is actually a flue damper motor. On the side of it, is a switch to lock it open. Lock it open and see if that stops your no heat problem. If so, then the motor is wearing out. If not, then side it back to automatic.

 

[A Squared]

here are some pictures. Thank you very much for your time and help.




(4) circulation pump and release value (both were replaced together about a year ago)
View attachment 722193

That pressure relief valve is required to have a discharge line whcih terminates within 6 inches of the floor. Whoever has been working on this for you is not doing legal work.

 

[rlxyz0]

Lock

Thanks. I haven't tried that yet as the heater has been working fine over the last few days.