New Gas Boiler "short cycling"

Ismellelephant

I had a new Weil McLain Cgi PIN 4 gas boiler installed and it appears to be "short cycling". After 3 or 4 visits from the installer they are now claiming this is normal. Recently in 20 degree weather the house only reached 67 degrees despite the thermostat being set to 70 degrees, and all through the night the boiler would shut off and on every 1 to 2 minutes.
Shouldn't this boiler run constantly until the set thermostat temperature is reached?
Purging the air in the baseboard system and a thermostat replacement didn't solve the short cycling. Thanks for any info.

neilc

did you get air?

is the circ running?

post some general pictures,

system pressure, and temp at boiler?

pecmsg

Is there a 1st and 2nd floor?

kcopp

Running and firing are 2 different things. Sounds like the boiler is firing but will only give up some heat and not satisfy the zone.

Could be air. Could be improper circulator/ flow.

Ismellelephant

Thanks for the replies.

There is no air in the system, a purge was done.

It is a one floor ranch house, one zone and about a 1000 sq ft house.

Running and firing, when the boiler reaches 160 degrees, it fires up, in about a minute or two it reaches 180 and fires off. The circulator is very quiet but I believe it continues to circulate when the firing is in its off cycle. It just continues this over and over again.

In 40 degree weather the house will reach set temp even with the 1-2 minute cycling, but in 20 degree weather it fails to reach set temp.

I understand the firing off and on to satisfy the 160 to 180 deferential. But when there is a call for heat shouldn't the boiler continue to fire until the thermostat set temperature is reached instead of firing off and on?

This is the system pressure meter

Jamie Hall

At first impression, either there is still air — in the boiler circuit — or the boiler pump isn't circulating throug the boiler.