Zone 1 on while heat is off...

CtrlAltDefeated

Hello, I am not sure what is going on with my heating system. We have not turned on the het yet this year. When I got home from work it was 88F on the first floor. Of course I ran to the thermostat and checked to see if someone had turned the heat on…the system was off and the temp was set to 60F (outside temp 70F). The system is a 2 zone forced hot water system. Zone 1 is the first floor and Zone 2 is the second floor. Zone 2 seems to be working properly. Each zone has a circulator pump, no zone valves. Any help is greatly appreciated. Thank you.

Ironman

Are you sure that the house was hot because of the heating system? We’re the radiators, boiler, or piping hot?

EBEBRATT-Ed

Do you heat domestic hot water with this boiler? Can you post pictures.

CtrlAltDefeated

I'm positive the heat is coming from the baseboards. The pipes to and from the furnace are hot while the other zone is not. This is a tankless hot water system, the hot water coil is in the boiler. I can post pictures at the moment.

HVACNUT

If the circulator is not actually running, then it's likely a stuck flo valve, or internal flo check in the circulator itself.

If zone valves, it could be stuck open.

bburd

That type of system relies on flow control valves to prevent gravity circulation of hot water through the radiators when not needed. This may take the form of flow check valves, usually on the supply pipe to each zone, or internal flow checks ("IFC") at the circulators, which should be labeled as such.

The separate flow check valves have a knob or lever on top so they can be opened manually or set to "automatic". Sometimes they slip. If you have these, try operating the levers and leaving them in the automatic position.

Sometimes a flow check will fail to seat properly due to debris or wear.

it's also possible that faulty wiring in the thermostat circuit or relay may be keeping a circulator on when there is no call for heat.

EdTheHeaterMan