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Topic: Webasto SG 1553/12v controller Aqua hot 431 (Read 3450 times) previous topic - next topic

Webasto SG 1553/12v controller Aqua hot 431

My Webasto controller is dying and I am interested in rebuilding the board.  Does anyone have experience in this area that would be willing to share information on what needs to be replaced?  Any help or guidance would be appreciated!
Thanks
Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #1 –
We have a commercial member who rebuilds them, I have one on my coach now and it works great. I carry a spare along with flame sensor and nozzles.


Aqua Hot controller box repair
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #2 –
Depends on what the symptoms are. My only experience is with the older metal can version.

The electrolytic capacitors tend to fail as they age. The capacitors determine timing, I've had several that failed to stop the blower properly and cycled on/off. I've had success replacing the capacitors however other components can fail. A schematic of the circuit board would be great but no success finding one. On the older metal enclosed controllers the connector end can be pryed off and the ciucuit board slides out.

 If you know a little about electronic circuits and you're handy soldering it may be worth trying. Cost of new controllers is ridiculous and they last 7 years or so. I have two controllers and replacing the capacitors fixed both of them.

Capacitors are available from Newark Electronics and they're cheap.

 Controller Capacitors
2 ea  220 uf  Axial  16VDC    C1 & C3
1 ea  100 uf  Radial 25V        C4
1 ea    10 uf  Axial    63V        C2  (I believe this one controls motor purge time)
1 ea  470 uf  Radial 35V        C5
1 ea      10 uf  Axial  33V        C6
David Bethard
2003 U320 - 40ft. Build #6159
ISM 500hp
2006 Jeep Liberty CRD
2021 Honda Goldwing DCT

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #3 –
Quote from: David Bethard –
Depends on what the symptoms are. My only experience is with the older metal can version.

The electrolytic capacitors tend to fail as they age. The capacitors determine timing, I've had several that failed to stop the blower properly and cycled on/off. I've had success replacing the capacitors however other components can fail. A schematic of the circuit board would be great but no success finding one. On the older metal enclosed controllers the connector end can be pryed off and the ciucuit board slides out.

 If you know a little about electronic circuits and you're handy soldering it may be worth trying. Cost of new controllers is ridiculous and they last 7 years or so. I have two controllers and replacing the capacitors fixed both of them.


Capacitors are available from Newark Electronics and they're cheap.

 Controller Capacitors
2 ea  220 uf  Axial  16VDC    C1 & C3
1 ea  100 uf  Radial 25V        C4
1 ea    10 uf  Axial    63V        C2  (I believe this one controls motor purge time)
1 ea  470 uf  Radial 35V        C5
1 ea      10 uf  Axial  33V        C6


David, thanks for the input--Would you also know the numbers for the relays?
Thanks
Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #4 –
I had our silver controller box changed out when we first bought the coach. I kept the old box, and I am considering sending it to be rebuilt by Jim Frerichs, and keep it as a spare. the cost will be just under $400, with a core exchange. The question I have is....Is this " overkill "?? I sure wouldn't want to lose the function of the box while we are traveling in Mexico, but even Jim says that when people call to complain about the rebuild, it is usually something else. He also suggested getting  a spare flame sensor. Do these fail often?? They cost about $200 !!!  I just ordered spare nozzle and filters to take along. should I  get the sensor??
Glenn and Amy Beinfest
2001 36' U320
#5812
2014 Honda CRV

No Whining on the YACHT

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #5 –
I carry one, murphy's law says if you have it you never use it. I would hate to be on vacation and not have the two things that usually fail, controller and flame sensor. They are also very easy to change on the road. Over kill might be coil, igniters and fuel pump.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #6 –
the Saga continues--- I still have not been able to find the relays for the SG 1553/12V Aqua hot controller but I have got the capacitors all ordered. I did find that on my control board the C2 and C6 were both 10 uf 63V.  It seems that anyone with Knowledge about overhauling these controllers are pretty tight lipped.  In the  mean time I found a solid state SG 1553/12V replacement located in the UK for 211.98 GBH at todays exchange rate that comes out to about 278.00 USD plus  about 15.00 shipping with supposedly no duties.  I paid with pay pal and it seems they charged me about 4% for transaction fee.  If you pay with credit card some don't charge a transaction fee.  But with pay pal hopefully I won't loose credit card  no. to someone across the water.
The controller that is sold on RV aqua hot parts had a D at end of part number, where as the one in UK had a C.  I emailed the company and they assured me it was only A mfg number change with no difference in controller.  RV Aqua hot parts list it at 973.01
After exchange rate and pay pal cost I am paying 289.72 including shipping.  When It comes in I will install and run Aqua Hot system then report back on performance. 
I still want to overhaul the one I have, So if anyone can help with relay Mfg and part numbers I would appreciate it.
I guess I'll be the guinepig for this but I couldn't convince myself to pay 450.00 for overhaul or 973.00 for a new one
PS for 50.00 I'll have enough capacitors to overhaul 10 control units and over 20 was for shipping
Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #7 –
I forgot to include the company I ordered from it is
Heatso.com
Chris
They have emailed me and said it was shipped "here is to hoping I haven't been scammed"
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #8 –
The relays in these controllers are a very heavy duty relay. The points may have a small amount of pitting, A very gentle cleaning with fine Emory cloth will clean them right up.. Usually capacitors get fat when they fail.. There are several transistors on the board, It is a high possibility one of those could fail.... There is a test box made , the controller can be plugged into it and it tests each function separetly... If you can get the box tested you would know which circuit has failed.. Otherwise it is a hit and miss game..... Best of luck !

Dave
2001 U320 40ft
Build #5867
2003 Tracker
VE7DOD

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #9 –
Thanks Dave, I'm old school and tight,  Have been told that some of the relays get weak springs therefore won't stay closed.  Most of the parts I have found are inexpensive but haven't been able to get anyone to give up part no's on the 2 different relays.

From talking to some of the forum members that have had problems it was either relays or capacitors--not saying it couldn't be a transistor that just hasn't been problem that members I have talked to had!
Would love to get a test box if it wasn't of prohibitive expense.

I have been certified by Aqua Hot as a "Tech" and will be available when home if some one is in central Arkansas and needs Aqua hot service.  We have 50A hook-up and water if someone needed to stay overnight.

Since Rudy is in Houston area I don't think I will be interfering with his business, plus he has been doing it a lot of years and is very Knowledgeable of the systems.

Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #10 –
Quote from: Chris m lang –
I forgot to include the company I ordered from it is
Heatso.com
Chris
They have emailed me and said it was shipped "here is to hoping I haven't been scammed"

BTW the new controller came in, I ordered it on Saturday and it came on Monday-- put it in and turned system on, so far everything has worked normally, I have been running it of and on for past week and half
"here is hoping all is OK"
Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #11 –
If you look closely I believe the springs open the latching plate from the coils.. The magnetic coil closes the contacts.. So all the spring has to do is lift the weight of the latching plate... If you look at the coil closely you can see the activation circuit. And test it in the board.. If you have a Good solder sucker you could remove the coil and test it ..

Good Luck
Dave
2001 U320 40ft
Build #5867
2003 Tracker
VE7DOD

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #12 –
Hi Chris,
How is the new controller holding up.

Thanks,
Bob
The selected media item is not currently available.Bob & Faith Rozek
1997 U320 40'
Xtreme Remodel
2010 Scion XD

Re: Webasto SG 1553/12v controller Aqua hot 431

Reply #13 –
Quote from: David Bethard –
Depends on what the symptoms are. My only experience is with the older metal can version.

The electrolytic capacitors tend to fail as they age. The capacitors determine timing, I've had several that failed to stop the blower properly and cycled on/off. I've had success replacing the capacitors however other components can fail. A schematic of the circuit board would be great but no success finding one. On the older metal enclosed controllers the connector end can be pryed off and the ciucuit board slides out.

 If you know a little about electronic circuits and you're handy soldering it may be worth trying. Cost of new controllers is ridiculous and they last 7 years or so. I have two controllers and replacing the capacitors fixed both of them.

Capacitors are available from Newark Electronics and they're cheap.

 Controller Capacitors
2 ea  220 uf  Axial  16VDC    C1 & C3
1 ea  100 uf  Radial 25V        C4
1 ea    10 uf  Axial    63V        C2
1 ea  470 uf  Radial 35V        C5
1 ea      10 uf  Axial  33V        C6

So during initial inspection i noticed that the C2 and C6 are the same value at 10uf Axial 63v
Will order extra if anyone needs PM me
My unit was working good but since I'm changing the ignition unit this would be the other weak link. Proactively changing capacitors is good in my opinion. I know no one has touched them prior to 2007, so they are old and have been threw many summers.
Scott