Green Star Combi. 151

JSC

The boiler won’t heat up any hotter then 120 degrees when the heat is calling. The boiler seams to heat up just find when the domestic hot water is on. The house is currently 47 degrees. The house has radiant piping. 

Thanks in advance.  

GW

We need a bit more information. You might’ve lost circulation. If you take pictures of everything that looks like a control, might get lucky and figure it out

JSC

The Taco circulator is working. The flame light is on  but won’t get any hotter then 110-120. 

Thanks 

Ironman

Possibly the outdoor sensor is reading incorrectly which would cause the ODR to keep the water temp too low - if this is connected. A lot of installers don’t connect it.

If you have it and can find it, disconnect one of its wires and see if the boiler heats the water to 180*.

Ironman

I just noticed where you said that you have “radiant piping”. By that, I assume that you mean a radiant floor. If that’s so, then 120* is about the highest water temperature that should be used - assuming the floor was done correctly. If not, then anything is possible.

As mentioned, more info and some good pics would be helpful.

And don’t assume because a green light is on that the circulator is working correctly. It just means that there’s power to it.

hot_rod

If the boiler is running up to 120 and shutting off, for some reason you are not circulating out to the radiant system. Could be a pump is out, air lock, frozen pipes  plugged strainer, mis wired, etc
Did it heat adequately at some point?