Hello,
I have a wood boiler and oil boiler hooked togeather to heat my home. Problem is Downstairs Thermostat will not open zone valve and cirrculating pump will not start. All the other 3 in my home work great.
If I hold open zone valve manuall for the downstairs zone . The Pump with work and the zone will open. as so for the other valves I took thermostat apart on wall and joined wires and it still won't work but there is power on it because i can see blue spart. Is the basement zolve valve broke??? even if it will work if up hold it manual and pump and valve flow??

THank you for your time.