When you light your gas heater, get it lit, hold the button for the
required time, let go of the button and it goes out, you will either
need to replace the gas hold on valve or the thermocouple.
assuming that a known good source of gas is hooked to the unit and the
igniter is sparking when depressed. In addition to the igniter sparking,
it also needs to be in the correct location. It should be located just
behind the end of the gas burner about 3/8 ths of an inch and
approximately 1/4 to 5/16 ths of an inch from the burner. If the igniter
is too far forward or backward from where the gas exits the burner the
heater will be hard, if not impossible to light. Adjust the position,
carefully so that you do not break the igniter, with a pair of needle
nose pliers. When properly located you should get a nice big spark with a
bluish tint in the vacinity of the holes where the gas exits the
burner. Make any adjustments with the unit unplugged and the gas turned
When you light the heater you need the gas to be turned on,
but if it would lose its flame it needs to shut off automatically. This
is a safety feature to assure that the unit will turn off when any
problems are encountered.
The way that the shutoff is
accomplished by Reddy Heat is to use a hold on thermocouple. The heat
from the flame makes the thermocouple output between 18 and 28
millivolts which keeps the gas on. This can be checked with a DMM
Turn off the gas supply. Remove the thermocouple from the gas valve.
With the DMM set to the lowest millivolt setting place the black lead
to the tip of the thermocouple and the red lead to the outer casing or
ground. Relight the heater and if the thermocouple is good you should
read between 18 and 28 millivolts.
In addition some units use a
relay in conjunction with the thermocouple. You will have to determine
if yours does. Remove the bottom base, if there is one, otherwise locate
the relay. With the DMM set to ohms, measure the resistance of the
relay between terminals 4 and 6. With no power you should read infinite,
(open), and with power you should read less than 100 milliohms or a
short. If the unit reads bad, open both ways, replace it.
gas valve being held open by the flame the heater will run until the gas
runs out or it is shut off. If the flame goes out the thermocouple
quits outputting power and the relay opens, shutting the unit down.
Repair parts can be purchased at www.reddyparts.com