DIY Network

Airstream: Install New Furnace and Replace the Thermostat From "Classic Rides" episode DCLR-202

In this third segment of the second episode, host Kevin Tetz is joined by Neal Stultz from Suburban Manufacturing to install the new furnace and thermostat on the project 1970 Airstream. The furnace is the exact replacement for the original Suburban furnace of the project Airstream--and it fits easily to the existing ducts.

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Note: The furnace on the project Airstream is 30 years old. The typical life of most RV furnaces is approximately 10 to 15 years, according to Neal. In order to get the correct furnace for your particular trailer, estimate 1,000 BTU for every foot of trailer.

Removing the Furnace

1. Before taking the furnace out, remove the exterior furnace vent (figure A) and make sure the LP gas is turned off and the 12-volt battery pack is disconnected.

2. Remove the wiring by loosening the 12-volt wire and the thermostat wire, and then remove the gas line and disconnect the furnace wiring.

3. Take the front covering off (figure B) and remove the screw that holds the heater assembly to the furnace cabinet. Loosen the gas connection to the old furnace while someone else holds the line with a wrench. Now remove the heater assembly from the cabinet. To remove the furnace cabinet, loosen the screws that hold it to the floor and the screws to the duct work. Remove the cabinet.

Figure A

Figure B

	Figure C
	Figure D
	Figure E
	Figure F

Installing the New Furnace and Thermostat

To install the new furnace start by installing the new duct box (figure C), which gets screwed down to the duct and secured to the floor.
1. The gasket goes in place and the furnace assembly is laid on top of that and centered over the duct box and the furnace is secured to the box.

2. Next connect the electrical and the gas. The gas line from the new furnace is hooked up to the main gas shut off valve and finger-tightened at both connections (figure D). Tighten the fittings with a wrench. Check for leaks when turning the gas on.

3. Disconnect the power plug from the furnace. Tie the two supply red lines together and using a wire nut--connect it. The yellow ground wire connects to the white ground wire of the trailer. The blue wires are connected to the thermostat wires (figure E). Secure wire nuts with electrical tape. Then bundle the wires and tape them together. The quick connect plug in is connected into the furnace.

4. Now you can go outside and install the vent. Line up the exhaust--you have an intake and exhaust vent that overlap onto the heater. You must maintain 1-1/4" on the overlap of the exhaust port and a half inch on the intake port. Then you have a lock up screw that locks that all together. Caulk around that to prevent water from getting in.

5. To install the thermostat, remove the old one by unscrewing it from the wall, attach the wires to the new unit and fasten the front plate to the wall (figure F).

6. To install the front cover on the furnace, you must screw it on with two screws on the front.

In the final segment a new water pump will be installed on the project 1970 Airstream.

RESOURCES :

Water Heater/Furnace
Suburban Manufacturing
PO Box 399
676 Broadway St.
Dayton, TN 37321
Phone: 423-775-2131
Fax: 423-775-7015

Zurn Plumbing Products
Website: www.zurn.com

Water Pump
SHURflo Pump Manufacturing
Website: www.shurflo.com

GUESTS :

Mark Huggett
Zurn Plumbing Products
Highway 11 East
Commerce, TX 75428
Phone: 903-886-2580
Fax: 903-886-2583
Website: www.zurn.com

Neal Stultz
Suburban Manufacturing
230 Blackburn St.
Dayton, TN 37321
Phone: 423-775-0437

Jeff Grigg
Master Plumber
4621 Ellistown Rd.
Phone: 865-689-3999
Knoxville, TN 37924