Hi all,
We live in Montreal in a split level house. The house is not well insulated in the walls. The roof is well insulated. And the basement is not insulated at all (cement walls and floors exposed). We have a 1989 Lincoln oil furnace and a 2 year old heat pump. This is our first winter in the house.
We have an Aube TH146-N-U thermostat and the external thermometer. The system is set to switch to oil at -10C.
I have noticed some weird behaviour in recent days....
1) Yesterday it was -3C and medium winds. The HP & fan turned on for 30 second, then off. After a couple of minutes it went on again for 30 seconds, then off. After another couple of minutes it turned on again (and started burning oil -I could hear the burner). Turned off after about a minute. Then after another couple of minutes the HP turned on again and ran for quite a while (normal). Any ideas?
2) The thermostat is set to burn oil at -10C. Sometimes when it's around -9/-9C the heat pump can run for hours at a time, trying to maintain a steady temperature. It will not go up half a point above the set point (to turn off), nor down (to maybe switch to oil). So it keeps running. The thermostat has an interstage delay set to 30 minutes, for which I thought it would switch to oil if the HP cycle was not finished after 30 min. We go thru furnace filters like crazy...they're black after 1 month (maybe related to burning oil?).
3) I understand that the oil can be used to heat the system to speed up the HP defrost cycle. So far we have used about 200-250 liters of oil (approx 60 US gallons). Seems reasonable? We may have had a couple of colder days when oil was used exclusively.
4) I think the location of the thermostat might be involved in the problem. It's on the main floor in the stair well. I think there is a small "wind" in there which affects the thermostat. I covered the vent holes with masking tape. Seems to help a bit... I would like to change the thermostat for a more accurate one. This one communicates thru the old 2 wire system to a control box near the furnace. I would like to replace it with a traditional system that has multiple wires between the thermostat and furnace/HP. Also most importantly, we also have a 3 speed fan which is hard wired on high speed. It would be nice to have it on low speed when there is no demand, med speed for heat, high speed for AC. What do you recommend?
Any advice is welcome!
Happy Holidays to everyone!
Cheers!
Terry
We live in Montreal in a split level house. The house is not well insulated in the walls. The roof is well insulated. And the basement is not insulated at all (cement walls and floors exposed). We have a 1989 Lincoln oil furnace and a 2 year old heat pump. This is our first winter in the house.
We have an Aube TH146-N-U thermostat and the external thermometer. The system is set to switch to oil at -10C.
I have noticed some weird behaviour in recent days....
1) Yesterday it was -3C and medium winds. The HP & fan turned on for 30 second, then off. After a couple of minutes it went on again for 30 seconds, then off. After another couple of minutes it turned on again (and started burning oil -I could hear the burner). Turned off after about a minute. Then after another couple of minutes the HP turned on again and ran for quite a while (normal). Any ideas?
2) The thermostat is set to burn oil at -10C. Sometimes when it's around -9/-9C the heat pump can run for hours at a time, trying to maintain a steady temperature. It will not go up half a point above the set point (to turn off), nor down (to maybe switch to oil). So it keeps running. The thermostat has an interstage delay set to 30 minutes, for which I thought it would switch to oil if the HP cycle was not finished after 30 min. We go thru furnace filters like crazy...they're black after 1 month (maybe related to burning oil?).
3) I understand that the oil can be used to heat the system to speed up the HP defrost cycle. So far we have used about 200-250 liters of oil (approx 60 US gallons). Seems reasonable? We may have had a couple of colder days when oil was used exclusively.
4) I think the location of the thermostat might be involved in the problem. It's on the main floor in the stair well. I think there is a small "wind" in there which affects the thermostat. I covered the vent holes with masking tape. Seems to help a bit... I would like to change the thermostat for a more accurate one. This one communicates thru the old 2 wire system to a control box near the furnace. I would like to replace it with a traditional system that has multiple wires between the thermostat and furnace/HP. Also most importantly, we also have a 3 speed fan which is hard wired on high speed. It would be nice to have it on low speed when there is no demand, med speed for heat, high speed for AC. What do you recommend?
Any advice is welcome!
Happy Holidays to everyone!
Cheers!
Terry
