atwood OD4501, OD5001 User Manual

LITERATURE NUMBER

MPD 90307

Cold Weather Kit #90290

for On Demand Water Heater Models

•Installation •Operation •Maintenance Effective 5/8/2012

Kit Includes:

- Heater Assembly # 90296

o Ceramic Clips (2)
o Heater assembly
o Tie Wraps (2 Long, 4 Short)

- Insulation Tape (36”) (Note: must be cut

into 16”, 14” and 4” pieces)

- Instruction

This kit includes the components necessary to
provide protection of the lower extremities of the
water circuit from freezing.
Protection of the heat exchanger (control of the
burner) is accomplished with a low temperature
thermostat which was provided standard on the
unit. It will provide protection for the heat
exchanger to ambient temperatures as low as 15°
F.
This kit is for adding protection of the lower
extremities i.e. the water tubes and the
modulation valve. It operates automatically
when the internal water temperature drops to
38°F.

Thermostat Replacement: (Part must be
ordered separately, # 90311)This switch is

used to light the burner for a limited ignition
cycle of the burner when temperatures dip to and
below approximately 40° F. It is only effective
when the power (12 vdc) is on and the LP tanks
are not turned off during travel or storage. If
there is continuity (switch closed) when the
ambient temperature is above 60° F, it is faulty
and requires replacement.

OD4501 and OD5001

Cold Weather Kit Installation

1) Installation requires the disconnection of the
water lines, gas line, and electrical connections
in the rear of the unit and removal of the unit
from the RV to a bench.

2) First remove the upper tri-panel by removing
(25) screws, unplugging the pressure switch,
ignition control, relay and blower connection,
and lifting off the case, exposing the interior
components.

3)Next lay out the harness with the ground
eyelet at the grounding point with the existing
ground eyelet, the first and second ceramic at the
locations indicated, the pad behind the
modulation valve, and the thermostat close to the
inlet tube grommet.

4) Clip the ceramics and the thermostat in the
locations indicated.

Ceramic (2) and T-Stat Placement

5) Using the 4” piece of insulation and tie wraps,
remove backer from the heat pad and insulation
then place on the backside of the valve and tie
wrap securely in place as illustrated.

7) Attach Ground to the ground screw (at burner
mount) as shown, and plug lead from heater
harness into Blue lead at the fuse position.

Insulation

Tie Wraps

6) Wrap the tubes with insulation tape using the
14” piece on the front tube and the 16” piece on
the inlet (back) tube. Note: Begin at one end of
the tubes removing the backer as it is wrapped
spirally along the length of the tube. The
insulation should wrap around and cover the
ceramic heaters and t-stat.

Ground Screw

8) Reverse disassembly taking care to re-attach
all connections.

9) Re-install in RV.

Caution: Follow proper connection checks
assuring no gas or water leaks are present.