Foretravel Owners' Forum

Got around to doing some basic work on the aqua-hot.  Ours is a 431/12 which is a AHE-100-02S as near as I can determine.

In our 2000 the AH is located mid ship, in the middle of the main storage bay.  First task was to simply clean up the inside of that compartment which had 25 years of soot, grime and gunk.  Once done with that I removed the AH access cover which only had a couple of screws holding it in place, the other screws were in the bottom of that bay.

With the access cover off, I noticed the magic silver Webasto box was not attached to the head, it was simply sitting in the base as its mounting bracket was gone.  Moving on I disconnected the Webasto cables, loosened the nuts on the (2) swing arms so I could pull back the burner head.

With the burner back and rotated away, I got to see some goodies.  First up, a dead mouse towards the back, along with the requisite turds.  With the mouse removed, I found (3) polytube 90 degree bend supports lying in the far right corner, no idea why they were removed and left there.  I also found one of the relay clips lying in the base pan.  Last was the cover edge trim. It was intermingled with the wire harness which must have fallen off at some point.

Back to maintenance: cleaned the photo disk / sensor, cleaned the combustion / swirler, new nozzle, adjusted the electrodes, cleaned the heat transfer tabs.  Replaced the head, reinstalled the edge trim, relay clip and bend supports.

I went to replace the radiator cap, and it literally fell apart in my hand.  The relief tab broke off, then the cap came off.  I had to pick out all the bits and then finally removed the spring and seal.  Cleaned it all off and put on a new cap. I've never seen anything like that. Who knows how old that was.

Next, there will be fuel filter and radiator flush/fill; given the cap I don't think the fluid has been changed in a long time.

Couple of questions!

• Who is Rudy's yoga instructor?  Getting in position to loosen/tighten that rear swing bolt was something!
• On the face of the burner, where the flame sensor disk is located, there are (3) bullet style connectors.  The plastic insulators are shot,  I taped  over them for now.  Are those just standard connectors that I can splice or should I get a new cable?
• The loose Wabasto box is concerning.  Looks like the bracket is available as P/N WPX-362-107 ~$15.  Is there some obscure reason why that bracket was removed that I'm missing?

Thanks!

Namaste'

And I am VERY glad he didn't show me the latest dead mouse found in the belly of the Beest.  I've seen enough to last me for a while.

Steve, A number of years ago, after replacing the silver control box several times with rebuilt boxes, I decided that the box being mounted against the burner motor was overheating the electronics inside the box. I detached the box and moved it outside the AquaHot housing. Over time this didn't seem to make any difference. So when I finally bit the bullet and bought a new black box, I moved it back to its original spot. Thankfully I had saved the metal mounting plate.

Something like this may explain the missing mounting bracket.

(Incidentally, I have so far been very pleased with the modern black plastic control box.)

Same,  I remember a conversation about this somewhere and moved my box also.

Morning Steve,  being 5 ft 8 in and 160 lbs makes getting in there and laying on your side a little easier.  But still not fun.

Your heater model is 431/12 unless stated differently on label on heater.  My 03 is a 431/12, which are the best heaters AH made, in my opinion.  Metal pumps and Watt mixing valves are long lived but no longer used.

Mounting the Control Unit, silver box, onto the burner is fine or any place else is too.  I have left the stainless cover off of the burner area of my heater, stored it.  This lets the heat escape into the bay away from the box.  A new Aqua Hot 300 901 solid state encapsulated control unit, with pig tail plugs, is only $1029 from AH.  A rebuild box is fine too.  But a black plastic box made in the Ukraine that does not have the pig tail plugs the new AH box does is very suspect and rarely long lived.

You are most welcome to call if I can be of any assistance.  It is not rocket science so I believe you will do fine.  The only thing I can suggest that many folks do not know is as follows:

1). Tighten the nozzle once, loosen it 1/4 turn and tighten it a second time to seat the threads into the nozzle tower.

2). Torque spec for the J-bolts that hold the burner to the heater is 20 inch-pounds, not foot-pounds.  So for all men, that means "SNUG", not tight.  Breaking off the tabs on the heater means taking it all apart, bearings and all, to replace the housing.

3). With a new service and nozzle on the burner, run and fire the burner ONCE per month or more year round, no excuse not to.  This keeps fresh diesel on the nozzle so the fog spray pattern remains constant.  You can go 2 or 3 years between services, maybe even 4 years.  Leave it off for weeks on end, plan to service the burner.  Watching the exhaust pipe while firing determines the need to service.  Clean and clear exhaust, good to go.  Visible vapor or smoke, service needed.

We are snug this morning in 40 deg temps with our AH cycling on and off just fine.  All the very best.

To clarify my earlier post, the new control box that I am very satisfied with is the solid state encapsulated unit. I guess I used an inaccurate description.

Richard, the Ukraine box is shaped like the silver box and is black plastic.  Very pleased for you having the 300 901 control unit

Thanks Rudy,

Any thoughts on this one, or is it not something we need to address further?

Please call me.  7 one 3.  8 one 8. 3234

Rudy,  thank you very much for taking the time to walk me through the details, much appreciated  ^.^d

Steve, were they the same as butt connectors?

The connectors for the flame sensor are round bullet connectors.  You twist them to break the friction and pull them apart.

The plastic coverings get hard and crack off over time due to heat.