Heat call for the past 2 plus hours and unable to reach target.

Ben_Nash

Thermostat is set to 71. The boiler takes about an hour to reach the target. It calls the boiler like 30 mins later. This has been the case since Friday night when the cold front arrived dropping our temperature to -15 degrees(feels like temp).

Then early this morning around 6AM when it's suppose to be warmer than last night by 10 degrees, the boiler has been taking 2 plus hours and still calling unable to reach 71 degree.

You can see from this picture that my boiler is taking longer time starting 6am. When I noticed, I had to step in and manually stop the call to give it 20 min break. https://imgur.com/a/JaP4b7S

dabrakeman

Interestingly you can run 2 hours without the system starting to build pressure (i.e. you manually turned it off without the pressuretrol doing so). This may indicate that your boiler is properly or certainly not over-sized to the connected radiation or that you are underfiring for some reason. Has your boiler been cleaned (burners cleaned and water chamber flushed out) in recent years? Clogged burners and huge amounts of sediment can reduce the boiler efficiency. 10F even with a good wind shouldn't be something a system should not be able to keep up with. Are your radiators all getting hot all the way across? Do you have your pipes insulated in the basement? Has there been any modification to the original radiator layout in the house that you are aware of (i.e. some removed)? I'm just a homeowner myself but you should get some good advice on this forum as long as they haven't all started dipping into the Christmas cheer already . The more pictures and information about your system you can provide the better.

Ben_Nash

There's pressure building up and most likely been short cycling. I just don't know what time it started after the boiler being called. I had short cycling issue last year. The boiler would run non stop throughout the night when it's below 20 degrees. Cracked my boiler. This year, I had a brand new boiler installed and the technician do the pipes correctly. The technician did the measurement and supposedly got me a proper size boiler. I thought it would resolve my issues. Guess not.

I insulated my main pipes in the basement but not the ones leading up to the units and they are concealed.

I am just curious is it normal for a boiler to run for so long and so often for these cold nights.

pecmsg

Running nonstop did NOT crack your boiler!

What size was the old boiler and what size was it replaced with?

Some pictures of the boiler and piping in one shot would help.

JUGHNE

Can we see your boiler piping, floor to ceiling? A few angles?

dabrakeman

Your data (looks like an Ecobee plot) does not show any sign of short cycling currently.

I don't think your situation is normal unless you are both under radiated and under boiler sized or you have a huge egress of cold air somewhere.

What is the actual temperature in your house based upon good old fashioned thermometer readings.
Not sure if you are controlling off the thermostat or a remote sensor but maybe your themostat is on a cold wall and not reflecting actual temperature in the house.

ratio

Are you using any setback at night? 'Cause those won't work very well once the temperature gets down to around design. Like it is now.

JUGHNE

And with everything in the area running full bore, your gas pressure may be down.

It may be noticeable on gas cooktop burners, if you have them.

dabrakeman

ratio said:

Are you using any setback at night? 'Cause those won't work very well once the temperature gets down to around design. Like it is now.

From the data chart it is not in a recovery that they are seeing the long cycles. Constant 71F.

The 71F is being attained but takes a long time to recover from the swing drop at end of the last cycle. The thermostat appears to be allowing a large swing before calling for heat again, which can be adjusted.

The rate of temperature drop after the boiler shuts down looks pretty fast to me (just comparing to my big old poorly insulated house at 3F with 25mph winds).