Anyway to disable oil burner in dual-fuel HVAC?

[benze]

Hi,

I've run into a small glitch with my dual fuel. I have a dual-energy HVAC system with a Carrier HP with an oil furnace. Standard run-of-the-mill Carrier thermostat that came with the HP and a dual-energy relay board.

My problem is that my oil delivery company failed to deliver oil and my tank is on empty. I've put in a call to refill the tank, but it will take 24-48hours. Currently, the furnace runs (there is probably just enough left in the bottom of the tank), but I am afraid that it may dry out the tank and then I would be forced to purge the line, which requires an additional service call (extra costs). (Not sure how to purge it myself, nor do I want to mess with the dirty oil...).

Current weather around here is roughly -7C to 2C. I figure that just the HP will be enough to heat the house.

The question is if there is a way I can disable the oil burner until I get the tank filled without disabling the HP? I tried disconnecting the white wire from the relay-board to the furnace relay, and it does disable the burner from firing, but since the thermostat (and HP) don't know that the oil burner has been disconnected, they still try to fire up the burner every so often to defrost and/or to produce more heat to raise temp more quickly.

Am I stuck? Is there anything I can do temporarily for the next couple of days to rescue the situation?

Thanks!

Eric

[VTP99]

Does your oil furnace have a on/off switch ?

[benze]

Does your oil furnace have a on/off switch ?

If there is, unfortunately, I cannot seem to find one for the burner itself. There is a breaker for the furnace which is seperate from the HP, but shutting that down obviously shuts down the blower and the thermostat, so that doesn't really help.

Otherwise, I have a Brock oil burner, with a Honeywell reset switch but nothing that would turn the burner on or off independently of the rest of the system.

And since I disconnected the lead from the relay board, the HP doesn't seem to like it very much, and the house temp has dropped to 16C.

Thanks,

Eric

[VTP99]

What will cost you more a oil service call or the charge to purge the line ? A service tech can disable that with no problem. I am not at liberty to give you DIY advice per the site rules. Sorry

[benze]

What will cost you more a oil service call or the charge to purge the line ?

Not sure what you mean by an "oil service call". Oil delivery is on its way, but they only promise 24-48 hours.

I guess the biggest question I had is if it was even feasible to disable the burner in such a manner, given that the HP relies on the burner to do its defrost cycles, and if so, how it would affect the HP if the burner was not firing.

Does a burner typically have an on/off switch that is separate from the rest of the system? Would that control only the burner itself, or the blower as well?

Thanks,

Eric

[VTP99]

[QUOTE=benze;9649492]Not sure what you mean by an "oil service call"
.the HP relies on the burner to do its defrost cycles, and if so, how it would affect the HP if the burner was not firing.

Does a burner typically have an on/off switch that is separate from the rest of the system? Thanks,

Eric,
"oil service call" Your HVAC service co.
The HP defrosts itself by going into a/c mode with no condenser fan running.
All electric HP's can run some backup heat strips to offset the cool air in defrost mode.
Most systems will have only one switch @ unit and one breaker feeding such switch.

[benze]

The HP defrosts itself by going into a/c mode with no condenser fan running.
All electric HP's can run some backup heat strips to offset the cool air in defrost mode.

I don't understand what you mean by the backup heat strips. I don't see how they would help if they are located in the outdoor unit, unless the unit didn't go into a/c mode.

Once in a/c mode, don't you need warm/hot air from the burner to compensate against hte cold coming off the expander head in the ductwork?

Thanks,

Eric

[VTP99]

I don't understand what you mean by the backup heat strips. I don't see how they would help if they are located in the outdoor unit, unless the unit didn't go into a/c mode.

Once in a/c mode, don't you need warm/hot air from the burner to compensate against hte cold coming off the expander head in the ductwork?

Thanks,

Eric

"All electric" heat pumps w/electric furnace can run the HP with the heat strips @ the air handler or fan coil simultaneously. Your duel fuel will do this only in defrost mode.

[beenthere]

Get 15 gallons of kerosene and put it in your tank, and set the thermostat to 60(16C).

[skippedover]

[QUOTE=VTP99;9649592]

Eric,
The HP defrosts itself by going into a/c mode with no condenser fan running.
All electric HP's can run some backup heat strips to offset the cool air in defrost mode.

This isn't true. Many HPs use either gas or oil units as the aux heat source for defrost. The true answer is that yes, the HP will defrost using the AC cycle but you'll chill the house during the process. It shouldn't take too long but you will feel the ill wind while it's defrosting.
Most systems will have only one switch @ unit and one breaker feeding such switch.

This again is not accurate. On a hybrid heat system using oil or gas furnace as the aux/supplemental heat, there should be a serviceman's switch at the furnace, a circuit breaker for just the furnace, a circuit breaker for the heat pump and a disconnect at the outdoor unit for the heat pump.

As Beenthere stated, go to your local service station and pick up 5 or 10-gallonsn of diesel fuel. Dump it through the fill pipe into your oil tank and you're all set. The diesel will burn the same as the #2 fuel oil. You won't be able to tell any difference at all.

[VTP99]

[QUOTE=skippedover;9650562]

This again is not accurate. On a hybrid heat system using oil or gas furnace as the aux/supplemental heat, there should be a serviceman's switch at the furnace, a circuit breaker for just the furnace, a circuit breaker for the heat pump and a disconnect at the outdoor unit for the heat pump.

As Beenthere stated, go to your local service station and pick up 5 or 10-gallonsn of diesel fuel. Dump it through the fill pipe into your oil tank and you're all set. The diesel will burn the same as the #2 fuel oil. You won't be able to tell any difference at all.

Try rereading the thread. We were talking about his furnace switch being able to seperate the burner from the blower. Read his last line of post #5. He knows he has a breaker for each unit in his post #3. Also read the last line of my post #8. I was explaning the operations of a "all electric" system. Do you understand ?

[Texanna Slim]

Ditto on the kerosene, but, why not diesel?

[benze]

On a hybrid heat system using oil or gas furnace as the aux/supplemental heat, there should be a serviceman's switch at the furnace, a circuit breaker for just the furnace, a circuit breaker for the heat pump and a disconnect at the outdoor unit for the heat pump.

Have one circuit breaker for the furnace and another for the HP (as expected). Also have a disconnect at outdoor unit for heat pump (although hidden in such a hard-to-get-to-area burried place, not really all that useful).

As for the furnace, though, no service man switch. The line from the breaker feeds directly into a White Rodgers transformer which then feeds into the furnace (haven't traced much further than that, but it looks like the output goes to to the burner and to a timer relay to activate the blower).

Am assuming that the serviceman switch would be somewhere between the WR transfo and the furnace? What difference would that switch be vs me just unplugging the W terminal from the dual-fuel relay board output which feeds the burner relay? Am still unsure as to why unplugging the burner relay failed to work properly. I would have expected the HP to run its normal course, but just with the burner not firing.

Thanks,

Eric

[beenthere]

Ditto on the kerosene, but, why not diesel?

Around here diesel fuel is more expensive then Kerosene because of the road use taxes on it.

[TriWorksInc]

If I were you, I would ask your local HVAC service company about a Rocket Fuel gauge. This may help you avoid future oil delivery issues. It is a wireless gauge that can be installed on the oil tank and a level indicator placed somewhere inside the residence that is very obvious for you to see, so you know you are low on oil. I have one and also supply my customers with this if the tanks are in places like under a staircase or in a garage or worse a stinking crawlspace that no homeowner will enter unless its an emergency. Good Luck fueling up.

[kmankess]

Detailed technical advice is not allowed. Please review our site rules.

Mod Team

[kmankess]

Sorry! I did see site rules but didn't see mention of not answering. But I did see not asking.

[bfsman]

so you have forced hot air by oil with a heatpump?it should be set up to select the most eff.way to heat based on outdoor temp.its not hard to do i set mine up at a 35.as far as shuting off the burner you will find very cold air coming out of your ducts during defrost and most likely the heat pump wont be enough in cold weather.

[skippedover]

By now the guys either frozen or he's gotten some oil. But the problem is that is he turns off the oil furnace electricity, he's also killing the 24-volt control circuit and therefore turning off the HP.

I know all about electric systems and that's now what the chap was asking about. He was asking about an oil fired dual fuel system. So someone's comment about electric heaters is inappropriate because he doesn't have electric heaters, he has an oil furnace.

Since we can't give specific instructions due to the danger of personal injury or property damage, the easiest solution and most intelligent is to put some oil in the tank. If that's kerosene and he can find that easily, then great. If it's diesel, then so be it. Around our area you can't find kerosene very easily but diesel is readily available 24/7. I was just trying to give him some options with fuels that would meet his needs.

[catmanacman]

lower the temperature that the system switches from heat pump to oil