Furnace help

[glennemay]

I have a hydroflame 79/80 in my 1996 Lance 11.5. It worked great last year before I unlocked her for the winter. I just put it back on and off course New England is not going to let go of cold nights. I need to get it workind get again.

The fan kicks on as it should. I have formed the instructions in the manual to a T with one exception. I do not have a valve that I can turn on and off on the gas line.

A I can assume is that this is some sort of automatic valve system that flows fuel when it needs to.

I get no ignition in the furnace athe all.


If anyone has any suggestions I am open. To almost anything.

Thanks

[Boon_Docker]

Kayteg1 wrote:
I will not read all long replies here,
but comparing pilot -light appliance to one having ignition/control board is like comparing carburetor car to one having digital fuel control and knock sensor on each cylinder.
Or like comparing rolling pin to bread machine.

:?

[glennemay]

Just wanted to follow up..

I had to purchase an inspection camera to see the sail switch. Which happens to be located at the VERY rear of the furnace. a few healthy flicks later and it started working. has been every since.

I know i am going to have to replace this at somepoint in the near future. But at least I have heat during the early season runs.



Thank You

[wa8yxm]

Glad I could be of help.. NOW. Just because the sail is not sailing does not mean the switch is toast.

The fan has to blow hard enough to sail it.. (low battery, and the thing I missed is a poor 12 volt connection on the supply side) also if you have heat registers blocked, or say covered with a throw rug or bath mat.. That can keep it from sailing.

But .. At least you now know where to start looking.. Again Glad I could help, thanks for letting us know what it was.


And to the person who said Compairing Pilot light devices to DSI is like a Bread Machine to a rolling pin (you do not use a rolling pin making bread) I agree, which is why I stated the document I published applied ONLY to DSI, not to Pilot Light. Or did you miss that.

[PaulJ2]

Sail switch is probably just stuck from setting all winter. If possible reach in with something and physically move it back and forth carefully a bit.
Had a furnace that did every spring but after that worked all summer/fall.

[glennemay]

wa8yxm wrote:
This document is generic for both furnaces and water heaters.. I'm told I missed one possible error..

NOTE: THis is for Direct Spark Ignition Furnaces. If you have a pilot light (I suspect you do not) major mods are needed.

When the T-Stat calls for heat the control board starts the blower (1)
The blower blows closing the sail switch (2)
The control board then opens the gas valve (3) and begins sparking (4.1)
Gas Flows (5) And ignitets (4.2)
The flame heats the flame sensor (5)
The flame sensor sends .480 volts to the control board (6)
which then detects the .480 and continues operation (*)
When the T-stat says "Enough already" (RV is now warm)
The control board shuts off the gas flow (*)
and then turns off the blower after a cool down (*)

*: At nearly every step the control board is involved. IF IT IS BAD, things will not work.. I recommend replacement boards from Dinosaur boards.. When Mine went out the Dino board was less than half the price and when opened the box the quality of construction and workmanship, and then design was very clear to my trained eyes.

1: No 12 volt to furnace, blower motor shot
2: Low 12 volt, air ducts clogged, blower "obstructed" bad sail switch
3: Bad solenoid, Clogged Gas Jet
4: .1: Bad ignition circuit (high voltage) on control board. .2: Points too wide (Very common it seems)
5: These do not often fail but they can
5: Bad connection, NOTE:
5 and * Bad wire.

* applies to all steps by the way So does bad wire/connection.

It appears as if the sail switch has made an early retirement.

I jumped past it today and was rewarded with an immediate spark. unfortunately I was unable to continue troubleshooting due to some personal commitments.



The problem I am having is the sail switch is in the back of the furnace and is behind an exhaust hose that is coming from the front. From what I can ascertain I need to remove the entire furnace from the camper in order to replace the switch.

Is there a way to determine which sail switch is in here without taking the old one out? Just trying to minimize the amount of downtime.

[John_Joey]

I'm going to jump the gun and give you a cheap and easy fix. The reason why is because my neighbor had your setup and after pulling the furnace and going through all the systems it turned out to be this.

Pull the cover off the furnace and you should see the high tension wire. Gently pull that off the sparker and clean the connection. See if that fixes your problems. Could be the Achilles heel of that model.

[Kayteg1]

I will not read all long replies here,
but comparing pilot -light appliance to one having ignition/control board is like comparing carburetor car to one having digital fuel control and knock sensor on each cylinder.
Or like comparing rolling pin to bread machine.

[wa8yxm]

This document is generic for both furnaces and water heaters.. I'm told I missed one possible error..

NOTE: THis is for Direct Spark Ignition Furnaces. If you have a pilot light (I suspect you do not) major mods are needed.

When the T-Stat calls for heat the control board starts the blower (1)
The blower blows closing the sail switch (2)
The control board then opens the gas valve (3) and begins sparking (4.1)
Gas Flows (5) And ignitets (4.2)
The flame heats the flame sensor (5)
The flame sensor sends .480 volts to the control board (6)
which then detects the .480 and continues operation (*)
When the T-stat says "Enough already" (RV is now warm)
The control board shuts off the gas flow (*)
and then turns off the blower after a cool down (*)

*: At nearly every step the control board is involved. IF IT IS BAD, things will not work.. I recommend replacement boards from Dinosaur boards.. When Mine went out the Dino board was less than half the price and when opened the box the quality of construction and workmanship, and then design was very clear to my trained eyes.

1: No 12 volt to furnace, blower motor shot
2: Low 12 volt, air ducts clogged, blower "obstructed" bad sail switch
3: Bad solenoid, Clogged Gas Jet
4: .1: Bad ignition circuit (high voltage) on control board. .2: Points too wide (Very common it seems)
5: These do not often fail but they can
5: Bad connection, NOTE:
5 and * Bad wire.

* applies to all steps by the way So does bad wire/connection.

[darsben]

glennemay wrote:

glennemay wrote:
I have a hydroflame 79/80 in my 1996 Lance 11.5. It worked great last year before I unlocked her for the winter. I just put it back on and off course New England is not going to let go of cold nights. I need to get it workind get again.

The fan kicks on as it should. I have formed the instructions in the manual to a T with one exception. I do not have a valve that I can turn on and off on the gas line.

A I can assume is that this is some sort of automatic valve system that flows fuel when it needs to.

I get no ignition in the furnace athe all.


If anyone has any suggestions I am open. To almost anything.

Thanks

Thank you all for your suggestions. I did locate the wires to the sail switch. Unfortunately, I am unable to get to it because of it's location. It is in the rear of the furnace and I need to remove the unit from the camper.


So if I jump the wires for the sail switch it should open the valve?



I did check on the propane. Everything else works. Stove, water heater, fridge.




Thanks again.



Glenn

Yep jumping the sail switch wires together would allow flow IF the sail switch is bad.
Make the connection AFTER THE FAN is turning not before to minimize potential adverse outcomes.

[glennemay]

glennemay wrote:
I have a hydroflame 79/80 in my 1996 Lance 11.5. It worked great last year before I unlocked her for the winter. I just put it back on and off course New England is not going to let go of cold nights. I need to get it workind get again.

The fan kicks on as it should. I have formed the instructions in the manual to a T with one exception. I do not have a valve that I can turn on and off on the gas line.

A I can assume is that this is some sort of automatic valve system that flows fuel when it needs to.

I get no ignition in the furnace athe all.


If anyone has any suggestions I am open. To almost anything.

Thanks

Thank you all for your suggestions. I did locate the wires to the sail switch. Unfortunately, I am unable to get to it because of it's location. It is in the rear of the furnace and I need to remove the unit from the camper.


So if I jump the wires for the sail switch it should open the valve?



I did check on the propane. Everything else works. Stove, water heater, fridge.




Thanks again.



Glenn

[Dusty_R]

Also if you are not plugged into 120 AC and your battery is low, the fan in then furnace will not run fast enough to activate/close the sail switch.

Dusty

[ksg5000]

Also - have you tried lighting your stove top burners? It will verify that you actually have propane gas and it will also tend to clear out air in the line which might otherwise prevent your furnace from starting.

[Calicajun]

Lots of threads on this subject in this forum. I know, I started one a couple of months back. My heater was acting the same way, it turn out to be the circuit board. The sail switch and circuit board are the two most common problems with heaters.

[darsben]

A sail switch is located near the squirrel cage. When the cage rotates the airflow causes a little sail like arm on the switch to move and close the switch. When the switch is closed the gas valve is then allowed to open provided all else is well.
I think the service manual for your furnace is located at

http://bryantrv.com/docs2/docs/hydroflameold2.
If not look through
http://bryantrv.com/docs.html
and see if the right one is listed