Log In | Register
Skip to main content
Topic: How to test a water heater circuit board (Read 12 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.
How to test a water heater circuit board
Yahoo Message Number: 112269
The Atwood water heater on our '02 30' will not ignite.  The fuses are OK.  I have blown out the burner tube.  The thermal cutoff appears to be good, i.e, it does not show signs of having melted due to excess heat caused by obstructions.  I have removed the circuit board http://www.amazon.com/dp/B0007XU4EC/ref=nosim/> and want to test it.  Can I do that with a digital multimeter or should I take it to an RV repair shop?

Chris Horst Arvada, CO
As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Formerly: 2002 30' IB
Re: How to test a water heater circuit board
Reply #1 –
Yahoo Message Number: 112270
Quote
The Atwood water heater on our '02 30' will not ignite.  The fuses are OK.  I have blown out the burner tube.  The thermal cutoff appears to be good, i.e, it does not show signs of having melted due to excess heat caused by obstructions.  I have removed the circuit board  and want to test it.  Can I do that with a digital multimeter or should I take it to an RV repair shop?

Chris Horst Arvada, CO
Chris, you might take a look at this.
http://tinyurl.com/2g8lht3 I had similar problem and had to go out and wiggle that brown wire to get it to ignite.  Finally cleaned the terminals and used dielectric grease.  No problem since.

Joe Hamm
Re: How to test a water heater circuit board
Reply #2 –
Yahoo Message Number: 112271
Quote

 
 The Atwood water heater on our '02 30' will not ignite.  The fuses are OK.  I have blown out the burner tube.  The thermal cutoff appears to be good, i.e, it does not show signs of having melted due to excess heat caused by obstructions.  I have removed the circuit board  and want to test it.  Can I do that with a digital multimeter or should I take it to an RV repair shop?

Chris Horst Arvada, CO

"Chris, you might take a look at this.
http://tinyurl.com/2g8lht3 I had similar problem and had to go out and wiggle that brown wire to get it to ignite.  Finally cleaned the terminals and used dielectric grease.  No problem since." Joe Hamm
Joe, thanks.  I have that manual and did do a lot of wire wiggling and terminal cleaning to no avail.  I probably need to take take off the plate in front of the solenoid valve to make sure there is no obstruction there.  In any event, I do want to test the circuit board before I put it back on.

Chris
Formerly: 2002 30' IB
Re: How to test a water heater circuit board
Reply #3 –
Yahoo Message Number: 112282
"Can I do that with a digital multimeter or should I take it to an RV repair shop?"

Chris

Atwood has a tester, MPD 32779, for their hot water heater boards.
 If you understand the operation of the board, after looking at the schematic, you can test most of the components and simulate operation, while the board is on the bench, using a couple pairs of jumpers, a 12-volt battery and a multi-meter.
It's easier to troubleshoot it when it in still installed.
Have you have seen this guide before?
http://bryantrv.com/docs2/docs/atwoodwaterheater.pdf> It contains a lot of good troubleshooting information, including a section on testing the electronic ignition board.
 The boards do not often go bad, the problem is usually another electrical or burner problem.
Did anything happen when trying to start hot water heater such as sparking or the flow of propane or was it completely non-responsive?

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: How to test a water heater circuit board
Reply #4 –
Yahoo Message Number: 112283
Quote
"Can I do that with a digital multimeter or should I take it to an RV repair shop?"

"Chris

Atwood has a tester, MPD 32779, for their hot water heater boards.
 If you understand the operation of the board, after looking at the schematic, you can test most of the components and simulate operation, while the board is on the bench, using a couple pairs of jumpers, a 12-volt battery and a multi-meter.
It's easier to troubleshoot it when it in still installed.
Have you have seen this guide before?
 It contains a lot of good troubleshooting information, including a section on testing the electronic ignition board.
 The boards do not often go bad, the problem is usually another electrical or burner problem.
Did anything happen when trying to start hot water heater such as sparking or the flow of propane or was it completely non-responsive?"

Larry
Larry, thanks for that doc.  I will read through its suggestions for troubleshooting.
 "Did anything happen when trying to start hot water heater such as sparking or the flow of propane or was it completely non-responsive?"
 The water heater worked fine when I had the LD in front of the house preparing for a trip.  Two days later on the trip, we drove through torrential rains for half a day.  That night it would not work.  It was completely non-responsive - no clicking noises.  Propane was on and working elsewhere.

Chris
Formerly: 2002 30' IB
Re: How to test a water heater circuit board
Reply #5 –
Yahoo Message Number: 112287
The Atwood control boards are exceptionally flaky, count on them failing at least every two years or so. Usually with no warning at all. Checks OK and works fine one day, dead as a door knob the next.  They are so bad that that many shops have them
Re: How to test a water heater circuit board
Reply #6 –
Yahoo Message Number: 112288
Quote
"The Atwood control boards are exceptionally flaky, count on them failing at least every two years or so."

-Dave '06 MB, Indianapolis
Wow, that's certainly news to me, thanks for sharing.
 Now that my original board is about to celebrate it's 6th birthday I'll be sure to expect impending failure.
 But you can be sure that if that should ever occur, I'll be replacing it with a Dinosaur board instead.

Steve S.
Lazy Bones & Jiggs
Steve S.
Lazy Bones & Cedar
2004 30'IB (Island Bed)
Yesterday is History, Tomorrow is a Mystery
Live for the day!
Re: How to test a water heater circuit board
Reply #7 –
Yahoo Message Number: 112294
"Wow, that's certainly news to me, thanks for sharing.
Now that my original board is about to celebrate it's 6th birthday I'll be sure to expect impending failure.
But you can be sure that if that should ever occur, I'll be replacing it with a Dinosaur board instead."

Steve

Guess our almost 8-year-old board is a goner too.
I really have not seen many bad boards, maybe it's a regional thing or has something to do with winter weather or the lack of earthquakes, something like that.
When it does fail, like you, it will be replaced with a Dino board.

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: How to test a water heater circuit board
Reply #8 –
Yahoo Message Number: 112301
Quote

 
 "Can I do that with a digital multimeter or should I take it to an RV repair shop?"

"Chris

"Atwood has a tester, MPD 32779, for their hot water heater boards.
 If you understand the operation of the board, after looking at the schematic, you can test most of the components and simulate operation, while the board is on the bench, using a couple pairs of jumpers, a 12-volt battery and a multi-meter.
It's easier to troubleshoot it when it in still installed.
Have you have seen this guide before?
 It contains a lot of good troubleshooting information, including a section on testing the electronic ignition board.
 The boards do not often go bad, the problem is usually another electrical or burner problem."
http://bryantrv.com/docs2/docs/atwoodwaterheater.pdf  I followed the step-by-step troubleshooting points in this very thorough document and after cleaning the 4 wire edge connector and other spade connectors with DeoxIT decided to reinstall the circuit board and try to start the water heater.  Eureka!  It fired up.

Thanks to all of you who offered suggestions.

Chris
Formerly: 2002 30' IB
Re: How to test a water heater circuit board
Reply #9 –
Yahoo Message Number: 112307
"Eureka! It fired up."

Chris

Glad you found the problem.
I wonder how many boards get replaced when the problem is an easily corrected bad connection. It usually takes a couple of year for the connections to get really bad if not regularly serviced.
 I have only been using DeoxIT for a few months and it seem to work great for restoring bad connection.  Dielectric grease is still a good preventative. Both materials belong is our electrical toolboxes.

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)