Re: No Heat on Second Floor
Posted by Greg Peters on November 10, 1999 at 19:16:13:
In response to Re: No Heat on Second Floor
: This is our first winter in a new house and I can't figure out why there is no heat on the second floor. I drained and re-filled the system and had to re-light the pilot because the furnace wasn't firing correctly. The system is a gas furnace with base-board hot water radiators. There appears to be two zones on the pipes in the basement (i.e. two sets of pipes with valves that can be open and shut) but there is only one thermostat. I've tried to put more water in the system, but the valve on the furnace blows out the old dirty water when I add too much. My next step is to add oil to the pump, it doesn't look too bad but I'm sure the previous owner didn't maintain it very well. Any ideas? Thanks.


There are several things that could be causing this. Here's what you need to check:
First, you say there are 2 valves, which appear to be for 2 heating zones, but you only have one thermostat. So you need to find out what controls the 2 valves. Some possibilities might be, the 2 valves are both controlled by the one thermostat (unlikely, but possible); or, one zone valve might be controlled by the thermostat, and the second controlled by another thermostat which was removed; or, the second valve might be a zone for your domestic hot water, in which case it's controlled by the water heater. So follow the wires from the zone valves and see where they go. Also, get a helper to crank the thermostat up to 90 deg. or so, while you watch the valves to see what happens. Does one open, or the other, or both? (There normally will be a delay of around 30 seconds between the time the thermo calls for heat and when the valves move.) If the second valve doesn't open, and it looks like its pipe goes upstairs, try opening it manually. There should be a small lever on the valve, usually it's in a slot with a notch to hold it open. Leave the valve open for several minutes and see if the radiators upstairs start getting hot. Oh, by the way, I just assumed the circulator pump is running. Check that too. You can feel the pipes just past the valves to see if they get hot when the valves open, but be careful, they get very HOT very QUICKLY.

Along with figuring out what controls the valves, you need to figure out what the valves do. If the second one is for DHW, it will have a pipe going to the hot water tank. If not, follow the pipes to see where they go. Maybe one goes to the first floor and the other goes to the second floor. Maybe they go somewhere else. Also look to see if there might be a third heating zone that's not controlled by a valve. Sometimes they'll do that to heat the basement. It makes no difference here (unless it goes upstairs) but it's something good to know.

Once you know what the valves are supposed to do, and what makes them operate, you should have the problem well in hand. If the second valve controls the second floor heat, and it doesn't ever operate, you might need a thermostat upstairs. If the valves are opening OK, and the pipe that goes to the second floor is connected to one of them, then you need to know why no water is going there -- probably air in the line and you need to bleed it. There are valves at the radiators for this purpose.

You might also check for shutoff valves in the lines. Sometimes these are put in so one component can be changed without draining the whole system. If one of those is closed you won't get heat in that zone. Also, don't overlook the possibility that your seller deliberately shut something off because of a leak.


Replies to this post
There are none.