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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have a boiler and steam radiators. The radiators are not

Customer Question

I have a boiler and steam radiators. The radiators are not heating up in the evening and at night. The house is about 60 - sometimes 55. Thermostat is at 70 but no heat. Then during the afternoon when the sun heats the house to maybe 68 (or close to the temp.set on the thermostat) the boiler/radiators will come on full force and get really hot. The thermostat was replaced. The boiler has been serviced. This was an issue last year and now again this year.
JA: Did you double-check the thermostat's settings? And what about the filters?
Customer: No filter. yes on thermostat
JA: Do you plan on doing the work yourself?
Customer: Maybe. If I can
JA: Anything else we should know to help you best?
Customer: no
Submitted: 11 months ago.
Category: HVAC
Expert:  WCohn replied 11 months ago.

Hello, my name is ***** ***** I look forward to helping you!

Expert:  WCohn replied 11 months ago.

Are the thermostats calling for heat?

Customer: replied 11 months ago.
I'm not sure what you mean
Expert:  WCohn replied 11 months ago.
Customer: replied 11 months ago.
Expert:  WCohn replied 11 months ago.

Okay. You should have pumps by your boiler is that correct?

Customer: replied 11 months ago.
No thanks
Expert:  WCohn replied 11 months ago.

No thanks? Is that to the auto generated phone call? I wish that was automatic

Customer: replied 11 months ago.
that was to phone cal. no we don't have pumps by the boiler
Expert:  WCohn replied 11 months ago.

What powers water through the radiators?

Customer: replied 11 months ago.
it's a steam system
Expert:  WCohn replied 11 months ago.

Okay in a low pressure steam system you most likely have a stuck valve

Customer: replied 11 months ago.
the boiler ignites and pushes steam through the system into the cast iron radiators when the house is at a warmer temp - say mid-afternoon. It works very well at this time. When the house temp is low no matter how high I set the thermostat the boiler doesn't come on until the rooms get warmed from the sun. It sounds strange but the system works well during those times.
Expert:  WCohn replied 11 months ago.

Well, I'm smart enough to know when I am not smart enough. I'm going to opt out and allow another expert to help you.

Customer: replied 11 months ago.
I don't know of any other way to describe the situation. So my apologies in that respect.
Expert:  Rick replied 11 months ago.

Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue. If my initial response doesn’t answer your question then let me know and we can continue our conversation.

The first thing to check is to clean out the piping leading to the pressuretrol. It's pretty common for this piping to get clogged with rust and when it does the boiler often operates erractically