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Home » Public Forums » GMCnet » 77 Royale Hot Water tank Model. Atwood? (Trying to figure out what hotwater tank I have.)
77 Royale Hot Water tank Model. Atwood? [message #261989] Mon, 15 September 2014 19:45 Go to next message
77Royale   United States
Messages: 461
Registered: June 2014
Location: Mid Michigan
Karma: 6
Senior Member
I have a 77 Royale with what Im pretty sure is an Atwood hotwater tank, Most of the stickers etc which are visiable are not readable. and Im wondering what specific model I may have, or where on the unit I may find a model or serial number. The outside access door is clearly an Atwood for sure.

It is LP gas with engine assist heat exchanger, and it pretty well matches up to the G6A-7 I have seen on line. (although those are manual pilot gas only)

The LP gas part of the heater itself is not working and I suspect its due to the circuit board above the burner being somewhat totally fried/ water exposed.

If anyone happens to have a decent working circuit board, and burner tube, I would be in the market for a cheap/reasonable price.

I know before you type it, "just throw the old one out and get a new one". Id like to spend that money on something more pressing if needed and want to see if just replacing the circuit board will get it working.

At this point I DO have warm/hot water when the engine is warm. There are NO leaks in either the water tank or the hoses coming and going to the engine. When I drained the tank the water was clear and no rust particles were found.

This leads me partially to think the tank itself maybe okay, and not used all that much as the board was bad. Id like to see if someone out there has a unit perhaps that had a leaky tank but otherwise had a good burner and board. Hence I need the correct model number.

If I cannot find that I will end up replacing the tank, and probably do away with the engine assist. Im not too big on long hoses with coolant in them running back there. Plus those heaters are almost twice the cost it seems. I can wait a half hour for hot water if needed.

Thank you all in advance, I can take a photo when its light out of that helps, and see about posting it here.


77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson carb and dizzy. Mid Michigan
Re: [GMCnet] 77 Royale Hot Water tank Model. Atwood? [message #261996 is a reply to message #261989] Mon, 15 September 2014 20:39 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
Wayne,

I'm sure you're right that your Royale has an Atwood water heater, for
which replacement parts should be readily available. However, dependent
upon your camping plans, there may be a viable alternative to a complete
repair. My Atwood operates properly on LPG, but we seldom use it since we
mostly stay where we have shore power. So, when we arrive, the engine
coolant loop has created enough hot water to last overnight. As soon as
we're parked, I flip on the switch which controls the 120 vac added heating
element. With that combination, we never run out of hot water for the
needs of the two of us.

The 120 vac heating element is a trivially simple addition: Just remove
the drain plug at the bottom of the tank and replace it with the heating
rod, then connect a 120 vac circuit to supply it. Here's one over-priced
source:

http://www.campingworld.com/shopping/item/hott-rod-water-heater-conversion-kit-6-gallon/47672

You can find better prices, perhaps in the FMCA magazine.

I think it's too easy to be concerned about the engine coolant loop for the
water heater. Just replacing the hoses every 10 years or so should prevent
any problem.

Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI & EBL,
Manny Brakes & 1-Ton, etc., etc.
www.gmcwipersetc.com

On Mon, Sep 15, 2014 at 8:45 PM, Wayne Rogewski wrote:

> I have a 77 Royale with what Im pretty sure is an Atwood hotwater tank,
> Most of the stickers etc which are visiable are not readable. and Im
> wondering what specific model I may have, or where on the unit I may find
> a model or serial number. The outside access door is clearly an Atwood for
> sure.
>
> It is LP gas with engine assist heat exchanger, and it pretty well matches
> up to the G6A-7 I have seen on line. (although those are manual pilot gas
> only)
>
> The LP gas part of the heater itself is not working and I suspect its due
> to the circuit board above the burner being somewhat totally fried/ water
> exposed.
>
> If anyone happens to have a decent working circuit board, and burner
> tube, I would be in the market for a cheap/reasonable price.
>
> I know before you type it, "just throw the old one out and get a new
> one". Id like to spend that money on something more pressing if needed and
> want
> to see if just replacing the circuit board will get it working.
>
> At this point I DO have warm/hot water when the engine is warm. There
> are NO leaks in either the water tank or the hoses coming and going to the
> engine. When I drained the tank the water was clear and no rust particles
> were found.
>
> This leads me partially to think the tank itself maybe okay, and not used
> all that much as the board was bad. Id like to see if someone out there
> has a unit perhaps that had a leaky tank but otherwise had a good burner
> and board. Hence I need the correct model number.
>
> If I cannot find that I will end up replacing the tank, and probably do
> away with the engine assist. Im not too big on long hoses with coolant in
> them running back there. Plus those heaters are almost twice the cost it
> seems. I can wait a half hour for hot water if needed.
>
> Thank you all in advance, I can take a photo when its light out of that
> helps, and see about posting it here.
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: 77 Royale Hot Water tank Model. Atwood? [message #261998 is a reply to message #261989] Mon, 15 September 2014 21:18 Go to previous messageGo to next message
SteveW is currently offline  SteveW   United States
Messages: 538
Registered: June 2005
Location: Southern California - Ora...
Karma: 1
Senior Member

Take a look here:

Dinosaur Electronics Home. High quality circuit boards for RV ...
www.dinosaurelectronics.com/
Home page for Dinosaur Electronics, a manufacturer of high quality ignitor boards and control boards for recreational vehicle furnaces, water heaters, ...
‎Ignitor Board Index page - ‎Replacements for Dometic - ‎Replacements for Norcold

Steve W
1973 23'
Southern California



Steve W 1973 : 23' Southern California

[Updated on: Mon, 15 September 2014 21:19]

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Re: [GMCnet] 77 Royale Hot Water tank Model. Atwood? [message #262002 is a reply to message #261998] Mon, 15 September 2014 22:18 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
There you go, Wayne, Steve's found just what you need. :-)

For my part, I should study those to see how to automate the ignition on my
water heater: The main reason we seldom use LPG is that I have to manually
light the pilot. :-(

​Thanks, Steve.​

Ken H.


On Mon, Sep 15, 2014 at 10:18 PM, Steve Weinstock
wrote:

> Ken -
>
> After all of the information that I've collected from you via this forum,
> I'm very pleased to finally be able to help you with something.
>
> Take a look here:
>
> Dinosaur Electronics Home. High quality circuit boards for RV ...
> www.dinosaurelectronics.com/
> Home page for Dinosaur Electronics, a manufacturer of high quality ignitor
> boards and control boards for recreational vehicle furnaces, water heaters,
> ...
> ‎Ignitor Board Index page - ‎Replacements for Dometic - ‎Replacements for
> Norcold
>
> Steve W
> 1973 23'
> Southern California
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: 77 Royale Hot Water tank Model. Atwood? [message #262005 is a reply to message #261989] Mon, 15 September 2014 22:51 Go to previous messageGo to next message
SteveW is currently offline  SteveW   United States
Messages: 538
Registered: June 2005
Location: Southern California - Ora...
Karma: 1
Senior Member
You're welcome Ken !!

With my initial post - I thought that you had posed the query... After re-reading - I realized that it was Wayne's inquiry and I edited my response to delete its reference to you. Nonetheless - my statement is sincere. Thank you for all of the information that you've provided here.

And Wayne - Good Luck. My Atwood water heater would ignite but then flame out within 7 to 10 seconds. I was just about to order a dinosaur board when I thought to give it one more try. You guessed it - it worked fine. I think I might have had a severely low house battery charge while it was failing. Haven't confirmed that yet - other than it seems to work now and my batteries are properly charged. Could have been a visit from Murphy too.

Steve W
1973 23'
Southern California


Steve W 1973 : 23' Southern California
Re: 77 Royale Hot Water tank Model. Atwood? [message #262019 is a reply to message #261989] Tue, 16 September 2014 06:52 Go to previous message
77Royale   United States
Messages: 461
Registered: June 2014
Location: Mid Michigan
Karma: 6
Senior Member
Thank you both. Looks like what I need is the universal with a post.

Seems to be a pretty simple hook up and 80 bucks or so may be worth a shot if I cant find a used board.

Its not a terribly pressing issue right now before I drain everything for winter. I like the idea of that Hot Rodd switch as well. I think we are around 80-20. Only dry camping 20 % of the time without a hook up.



77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson carb and dizzy. Mid Michigan
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