Attwood Direct Ignition Water Heater Problem

[leadman]

Our '87 Itasca has an Attwood Model G6A-4E Direct Ignition propane only water heater.
We have an intermittent problem as the overheat red light will come on. This will happen at times just after the switch is turned on or when the water heater has been on for a short while, but in both cases the water is not hot.
I have replaced the ECO and Thermostat along with making new wires. The old wires had corroded terminals and also the wires were showing green at the terminals. I soldered all the new terminals and installed shrink sleeving.
The past couple days it would take 4 or 5 trys to get the heater to work properly, today it fired right off with no problem.
I am thinking the Control Unit might be bad but do not have the info to test it with.
Any opinions??

[tmh462]

It could be simply the limit diode is giving up the ghost. Try removing it temporarily and see if the problem stops happening. The diode is on the circuit board inside the cover, and looks like a transistor in a clear vinyl sleeve.

[leadman]

Fixed the heater while in Wyoming. Replaced the circuit board for the measily sum of $182.00. Works fine now. Think it was the relay on the board, but as it was the original board from 1988 I thought it best to replace the board.