I heat my home with hot water baseboards - two zones, upstairs and
downstairs. Both zones are run on standard non-digital two-wire
Upstairs zone runs perfectly fine. No problem with the thermostat
Downstairs zone has a problem. If left alone, the thermostat seems to
maintain the heat it it set at. If I try to increase the temp by
moving up the lever manually, you can hear the boiler get ready to run
(zone valve opens, circulator starts), but then it clicks off and
stops. Moving the lever back down will sometimes cause the same sound
- as if it is ready to go, and then dies again.
I have replaced the basement thermostat with another non-digital one.
Any thoughts on a cause?