Gas and Oil Home Heating Furnaces - Thermostats for forced water heat (radiant)

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butterfly29
10-25-03, 01:43 PM
We bought a house made in 1959 and there are 2 thermostats. They both seem original and I believe are inaccurate. Are there specific thermostats that we need to get to replace them? The boiler is gas heated and original, but in good condition.
Thanks!

KField
10-25-03, 01:50 PM
Because you have 2 zones, it would be helpful for us to know what type of zone control valves you have. Or if you have 2 circulating pumps. You probably can use almost any kind of thermostat bur we can tell you better after you give us a little more info.

Ken
butterfly29
10-25-03, 01:57 PM
We have 2 pumps.

KField
10-25-03, 02:13 PM
Is each pump controlled by a relay? Hopefully you can determine that. The only reason we need to know that is because it could mean the difference between needing a low voltage or line voltage thermostat. If you have any other questions to help find out about the relays, post back.
butterfly29
10-25-03, 02:18 PM
How do I know if I have a relay? What is a relay?:confused:
KField
10-25-03, 02:34 PM
If you follow the wire from each of the pumps, they may go to a relay. It is a way for a low voltage thermostat to turn on a pump that uses regular house current. One pump wire may go to the main boiler control and the other may go to another control. Any description you can give will help.

Ken
butterfly29
10-25-03, 02:48 PM
above the two pumps are two gray cylindrical metal boxes. They are completely covered, but seem to have the same fabric covered wire that goes back into the wall from the pumps. Could these be the relays?
KField
10-25-03, 03:00 PM
Could be the relays but cylindrical sounds more like a zone valve. Either way, you have identified the fact that the thermostats are operated by low voltage. Now it would be a good idea to remove one of the stats and see if it uses 2 wires or if it may have 3 wires in it. If it has 2 wires, you can use any heating thermostat that is made for gas or oil.
butterfly29
10-25-03, 03:06 PM
Thanks for all the help. There is a red and white wire that come through the wall and hook up to the thermostat (on both). Would we be able to use a programmable one or do we have to stick with the normal kind since the system is so old?
KField
10-25-03, 03:31 PM
Programmable is fine. You should be able to get whatever kind you like. It will most likely be battery powered and that is good. Just use the R and W terminals and be sure to check the instructions for any settings that my need to be made to match your system for cycle rate.

Ken