Rinnai REU-VR3237WG Service Manual page 31

14. Anti-frost Heater Circuit (D
a) Disconnect relay connector D
inlet valve frost heater at the frost heater side. Normal 53
Faulty: Replace valve anti frost heater.
b) Disconnect relay connector D
the pipe frost heater at the frost heater side. Normal 618

Faulty: Replace valve anti frost heater.
15. Frost Sensing Switch
Disconnect relay connector (D
wires. At room temperature resistance should be > 1M
measure resistance. Resistance should be < 1M
switch. 
Infinity REU-VRM3237WG / HD250e REU-VRM3237WC
and D )
5 6
and measure resistance bewtween yellow wires on the
5
and measure resistance between the yellow wires on
6
) and measure resistance between yellow and yellow
4

- 26 -

. If normal proceed to b).

. 

. Cool switch to below 2
. Faulty: Replace frost sensing

then
Issue 1 - 19/05/09 ©Rinnai