Went to try and help a friend this morning (my first mistake 😉 ).
He has a small office building, and one side is two stories with each floor being a seperate office. The first floor tenants complained of uneven heat essentially. One area having weak heat from the rads. Two thermostats, both of which checked OK. Went downstairs and found that for the four total zones (that is to say, thermostats), there are only 3 circ pumps. From what I could see, it appeared that on the floor in question, one of the thermostats only fired the furnace, and the other ran the circ pump. I’ve never seen anything like that, but it would explain why there are more thermostats then there are zones. Unless there’s something I’m missing here… my assumption is that the first floor is just one loop and that there has always been uneven heat that was only an issue because we had a cold snap last week and (according to the tenant) the “cold” area is being utilized more than in the past.
Wierd but… any other ideas/suggestions or things to check?
TIA
PaulB
Replies
Two things come to mind, just from the description about single loop, uneven heating:
1. Maybe the pump is faulty or there is a blockage in the line, so that flow isn't what it ought to be.
2. There is too much baseboard heating surface for the flow, so that by the time the water gets near the end of the line it has cooled down too much to put out much heat. If this is the case, you might be able to tell by feeling the pipe into the hottest end (be careful) and at the outlet end. The outlet end ought to get hot also. To rectify things, you could slip some strips of cardboard onto the top of the tube fins over enough of the hot end so that the water doesn't lose heat as much there. Play with placement to get more even distribution.
3. Have your friend call a heating specialist and pay him money to fix.
There could be zone valves regulating the different zones. Same pump will operate two different loops. Perhaps the zone valve on one zone is kaput.
A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Sorry Calvin... I neglected to mention that my first theory was a bad zone valve but I'll be damned if I can see any at all... certainly none in the mechanical room. As far as I can see, the thermostats switch the pumps only... and the furnace from the bizaaro scenario I described.PaulB
Paul, I guess you checked that there was in fact movement of water by all the pumps?
Every fall I shut down the system, isolate the pumps and pull the caps on the impeller. Turn manually to see that it is free. On occasion they become " frozen up" and need a push for them to operate after having been shut down all summer.
Maybe-mis adjusted or blocked mixing valve somewhere? Are all the delivery systems the same-A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
the thermostat that you say runs the boiler also gets the circulator energized by the aqua-stat (c1 c2) the other zones are controlled by the thermostats and the aqua-stat is running the boiler on low limit which does not supply water as hot unless the thermostat controlling the zone from the aqua-stat is calling through the high limit, for heat. This can be corrected by installing a zone controller.