By Jon from San Diego on October 7, 2013
I have a couple of questions. The specs state that the depth is 6 inches. If it is installed recessed in a wall, will the unit only stick out 2 inches? Is there a blower kit? Is there a rear register, and does it have blower as well?
By Collin C. - NFI Master Hearth Professional on October 8, 2013
By Dave from Racine, WI on March 11, 2016
If I were to purchase the out of wall installation kit with this furnace, how much further would it stick out from the wall? Is it then is vented out of the top - back part of the furnace? What size of vent is used then? The automatic shut off, can that be used as a thermostat?
By eFireplaceStore on March 15, 2016
Answer:Per the manufacturer, the out of wall kit is 6 5/8 inches deep and allows the heater to be installed completely outside the wall, with the kit simply anchoring to the wall for support. The venting will continue to be routed out of the top of the unit, towards the back. It would have to be encased in a vent chase to hide the pipe. The venting starts as Type B 4 inch ovalized from the top of the unit and can be left as such or adapted to Type B 4 inch round. The unit comes with a basic thermostat for on/off operation.
By Elmer from Springer, New Mexico on September 22, 2013
My model GWT-35-1 natural gas heater will not light up. The pilot will light but gas won't go on to the furnace. I took the thermostat off and touched both wires, red wire and white wire but no spark (gas will not go on). I checked the outside electrical panel and there are no tripped switches. It has a reset button but I am afraid to push too hard and break it. Can you give me possible problems and how to fix them?
By Collin C. - NFI Master Hearth Professional on September 23, 2013
Answer:This unit is a standing pilot, millivolt style of appliance. This being the case, it generates its own electricity to operate and will not have any outside power to rely on. If the pilot is steady, voltage should be routed to the valve for it to operate.
To test operation, first switch the gas valve to the "on" position. Next, use a short section of jumper wire to jump between the "THTP" and "TH" terminals on the gas valve. This should manually active the valve. If the burner does not ignite, there is likely an internal issue with the valve or the pilot is not generating sufficient voltage.
By Colette from Montreal on February 20, 2013
I own a GWT35 natural gas wall furnace. I've had it 8 years and it worked fine. Recently, l had three occurrences of the pilot light just going off leaving me without heat until l realized what had happened. l re-lit the furnace and then it happened again after 5 days. Re-lit and it happened again after 10 days. lt's a good thing l am not going away.
l keep the area below the thermostat and pilot clean and there was no draft because all windows and doors are closed. l live in Montreal and temps are well below freezing! What could be the problem? l am worried now when l leave the house that it's going to go off again.
By Collin C. - NFI Master Hearth Professional on February 21, 2013
Answer:Most likely, the thermocouple in the unit is becoming weak or has a buildup of combustion byproduct that is causing it to produce a decreased millivolt output. The thermocouple (probe that the pilot flame heats) can be cleaned to see if that will resolve the issue. With the pilot light off and the unit cool, use a piece of fine grit sandpaper to lightly polish the thermocouple. After years of being engulfed in flame, the probe will become dark and will have a layer of buildup. When the probe appears clean, wipe it down with a damp cloth to remove any residue from the sanding. Allow it to dry and relight the pilot again.
If the pilot continues to go out, the thermocouple has simple gotten too weak and will need replacement.
By Dave from Racine, WI on March 14, 2016
If I purchase this furnace, model GWT35 , with an out of wall installation kit, how far will it stick out of the wall? Can I use the automatic shut off as a thermostat? What size of vent do I use for the chimney and is it a round one? Does the vent come out of the back of the unit or the top?
By Will M. on March 15, 2016
Answer:With the kit you have purchased, the heater will project into the room equivalent to the depth of the heater, which is 6". You may have to provide clarity for the shut off you are planning to use, but any standard millivolt On/Off thermostat may be used with this heater. This heater uses 4" oval B-venting installed on the top of the heater for vertical venting.
By Louie from Pico Rivera, CA on February 5, 2016
How do you start the wall furnace manually when the thermostat is not working?
By Will M. on February 5, 2016
Answer:You may use a section of jumper wire to jump between the "THTP" and "TH" terminals on the gas valve to test operation of the heater. If this ignites the burner, check your wiring or replace the thermostat. If this does not work, you may want to clean the pilot assembly or adjust the pilot flame to ensure the thermopile is producing enough millivoltage for the valve to allow flow to the burner. If this does not work, either the thermopile will need to be replaced or there is an internal issue with the valve.
By Connie from Laguna Beach, CA on May 24, 2013
Does the heater need to be ventilated to outside?
By Tyler M. - NFI Certified Specialist on May 24, 2013
Yes, this furnace must utilize Type B gas vent pipe. You can see venting details for this unit starting on page 6 of the owner's manual
By Jan-Hendrik van Leeuwen from Middleburg, VA on October 11, 2012
I am considering replacing my kerosene stove with a propane gas heater. I have the following questions regarding the ventilation of the Empire B-Vent Gravity Wall Furnace, model GWT-35:
1. How is this model ventilated; does it require the installation of exhaust pipe(s)?
2. Could this furnace be installed against the chimney that is currently used for ventilating my kerosene stove?
3. If so, could this chimney be used as a duct for the the furnace's exhaust?
By Collin C. - NFI Master Hearth Professional on October 12, 2012
Answer:This furnace features an ovalized 4 inch flue outlet, as it is primarily meant as a wall furnace. This allows the vent piping to be encased in a standard 2 x 4 wall without any clearance issues. An oval-to-round adapter is used to convert the B vent piping from a 4-inch oval back to 4-inch round, after the vent piping has entered the attic.
In your scenario, it is certainly possible to install this furnace in front of the existing chimney. You would need to use the "out of wall" furnace kit located on the accessory tab above. You would still need to use an oval to round B vent adapter, then run 4-inch liner venting up your existing chimney.
I do not recommend venting the furnace into your chimney without the 4-inch liner. Lack of a liner will cause the furnace to draft poorly and cause poor performance.
By Terry from Glenwood Springs, CO on July 2, 2014
I'm interested in replacing an old radiant heat gas furnace, but it's located between two rooms and provides heat in both directions. Do you have anything like that, or could I put two of these furnaces back to back. Radiant would be preferable, but forced air would be adequate.
By Chris C. on July 2, 2014
By Robert Gordon from albuquerque NM on November 15, 2011
installed 35,000 btu single wall furnace. Works fine, except the pilot goes out after about 24 hours of operation.
Vented directly up through flat roof with 9 feet of double wall vent pipe that is used directly from the furnace. Typical rain cap installed.
No CO and furnace seems to operate normally except when the pilot goes out.
Do you know what the problem is? The venting diagram shows insulated section of vent on roof, and transition to larger pipe. I did not do this. Is this a problem with venting, causing the pilot to go out? The voltage measurements are excellent showing the thermopile is working.
By Collin C. - NFI Master Hearth Professional on November 15, 2011
Answer:Most commonly, a misadjusted thermopile is what causes the pilot to extinguish. As you mention, the voltage reading are within specification, so this would not be the issue.
Improper venting can cause this issue, but it is usually not a routine occurrence. The pilot will usually go out at random and not at regular intervals. Please advise if it is going out at exactly 24 hours or if there is a little more variance, say by a couple hours.
By brad hoffman from las vegas on November 15, 2011
Do you sell the vent to this? It's the type b vent system.
By Collin C. - NFI Master Hearth Professional on November 15, 2011
Answer:We do indeed carry the type b venting for this unit and can assemble a quote for the needed pipe if you like. The unit also requires a type bw adapter to pass the pipe from the stud cavity the unit is mounted into, through the wall header and into the attic.