Spending money - on the ProHeat this time

[bobofthenorth]

So I'm back in the deep freeze and guess what?  My ProHeat XL900 (precursor to an XL45) decides it doesn't need to stay running. It pulled this crap back in November when we were leaving the country but I tore it apart and cleaned it up in Mesquite and it seemed to be working OK but not last night.  I was up about 4 times to reset it because it got a "start error". 

Today I crawled in there - memo to all you guys that are locating your hydronic systems - PUT THEM WHERE YOU CAN ACCESS THEM EASILY.  I tore it apart but everything looked pretty clean this time.  Clean but wet and I've suspected that the nozzle may be worn so I tracked down the local dealer and bought a new nozzle and new spark plug (they call it an igniter but it sure looks like a spark plug to me and its even hooked up to a coil)  While I was in there mucking around getting the combustion chamber opened up I noticed that the floor was wet.  What's that about?  The seal must have gone out of the circulating pump so I got one of those as well.  $485 later I'm halfway to a new system and still don't know if it will make it through the night.  Since we bought this rig 4 years ago I have put on a new combustion chamber, new blower, new makeup air compresser and now all this crap today.  If I could think of a simple way to take it out of the system it would be gone. 

I like the looks of the new pump though.  The original was a Johnson but it was a pretty wimpy little affair.  This one looks like a PUMP.  We'll see.

[TomC]

Well- I don't want to hurt your feelings-but because of the cost of the AquaHot system, I went with an Atwood 35,000btu propane furnace, Atwood 3 burner propane stove (only two propane items with a 20 gal tank), 2-10gal elec water heaters bought from Home Depot, reused the radiator powered heat exchanger with 2 14" electric radiator fans on it for heat going down the road.  This all cost about 1/4 of the AquaHot system.  In the 8 years (some has been working for 12 years-during conversion) I have had ZERO problems with any of these appliances.  Obviously a record that is not so with the AquaHot.  Maybe time to switch it out-there's a good reason propane is used-it is a proven and inexpensive means for heat (albeit not as safe as Diesel).  Once again, not trying to jump or hurt you-just showing a different system.  Good luck, TomC

[JohnEd]

Bob,

Try having it professionally serviced/repaired.  Sometimes you don't know what you don't know and watching that tech or reading his repair report might be a huge help down the road....pun intended.  You sound like you are buried in the thing.  They make hyd units that are propane fired and I wonder if yours doesn't have a conversion "kit".  Propane is most certainly less trouble but the fuel isn't cheaper and forced air will never be as comfy as water heating can be.

Good luck with this and do post the fix, please,

John

[Nick Badame Refrig/ACC]

Hi Bob,

You said the unit locked out and you had to reset it!  What code did it give you?

If all is ok now, then great. But if not, give us the codes that light up when it locks out.

Good Luck
Nick-

[luvrbus]

TomC, he is not working on a Aqua Hot system 

[bobofthenorth]

Whoever it was that suggested professional service - been there done that while Nathan Parker was still at Prevost Mira Loma.  It "worked" for about 7 months (fixed in April, didn't use it until November, quit more or less immediately).  It usually doesn't let us down completely - just enough to be a major PITA.  And thanks for the advice but over the years I have learned that, if its an easy troubleshooting situation then I can hire it done.  Otherwise the only person with enough vested interest to solve the problem is the guy in the mirror.

And Tom you didn't hurt my feelings one iota.  I agree 100% with the system you have.  This bus was converted when we bought it.  Pulling out the hydronics and putting in forced air isn't a practical option now.  This SOB is going to work or I'm going to find something that does.  End of story.

I had one fail-to-start last night, actually REALLY early this morning.  I changed the air filter element this afternoon so we will see how that goes.  It was smoking pretty badly this morning which is indicative of a plugged filter.  That's another thing that p's me off about this thing.  It has the most rinky-tink little filter element on it.  My JD riding mower has easily 8x the filter surface that this SOB has.

Nick this unit has a panel with LEDs that light up next to an indicator like "Start" or "Flame out" - right now what I have been getting is "Start" codes which essentially means that it didn't start - big news there!  I don't know of any way to throw a more detailed code than what is indicated on the panel.  The troubleshooting steps in the service manual for a "start" code are fairly elementary. 

[skipn]

Bob,

    I realize you probably already checked............

  It has happend on my house furnace a couple of times with a big filter on.

   There is a strainer on the fuel line going onto the housing of the unit.
After the filter..... That 90deg fitting houses the strainer.
Maybe check that they do get plugged.

FWIW   hate to see I guy look for dynamite!
Skip

[Nick Badame Refrig/ACC]

Hi Bob,

Skip hit it on the nose... those screens are always dirty  The only other problem that would cause your same scenario is air leaking into the fuel line.

You could have a cracked line at some point that the fuel pump could be sucking a air and fuel mix that will arise at start up. Especially after

sitting for a pierod of time.

Good Luck
Nick-

[buswarrior]

Replace with a Webasto?   

happy coaching!
buswarrior

[bobofthenorth]

Replace with a Webasto?   

Not that desperate -- yet.

I got a call from Chris http://www.gmbusguy.com/.  What a wonderful community we live in.  He called me out of the blue last night to offer some help.  He told me more in 15 minutes than I have learned in 4 years.  Then he gave me his friend Jim's number cuz he said Jim was the real expert.  So this morning I called Jim a couple of times and I think we have it whipped.  Turns out my fuel pump has likely not been working for the last 2 years - maybe longer.  The way these things work and where mine is located they can actually siphon fuel out of the tank and that is likely what mine has been doing for some time now.  I never bothered to check the fuel pump because most of the time it worked - I thought if I had enough fuel to burn for extended periods that must mean the fuel pump was working.  Shows what (little) I know.  Anyway, once I actually tested the pump and discovered that it wasn't pumping it was a pretty short trip to getting it fixed.  I happened to have a 12V inline pump unopened in the box.  Can't have too many parts when you travel.  So I jury rigged that into the system and it works like a charm.  I'm going to track down the right pump on Monday cuz this setup looks pretty boogy but for the time being I have heat and all is good.

Thanks to (almost) everyone who offered advice and a big thanks to the two guys that finally nailed the problem.

[buswarrior]

Test rig for these beasts involve boring out an old nozzle, grafting on a short pipe and threading a fuel pressure gauge onto the end.

Screw it in, and turn on to ensure proper fuel pressure at the nozzle...

Shoot, I should'a thunk before now... sorry Bob!

happy coaching!
buswarrior

[bobofthenorth]

Sorry but I gotta argue with you Ewen - that won't work on a 900.  See - I actually know how this works now.     You could do that ahead of the fuel regulator/diaphragm but not at the nozzle.  Proper fuel pressure at the nozzle is 0 PSI - atmospheric pressure.  That was exactly the nature of my misunderstanding.  I assumed that because I had flame most of the time I must have had a pump. 

The way these models work is the compressor blows through the nozzle and the venturi in the nozzle lifts the fuel from the diaphragm up to the combustion chamber.  The role of the regulator is to deliver 0 PSI fuel slightly below the level of the nozzle.

[Nick Badame Refrig/ACC]

Bw & Bob,

That is the purpose of the fuel regulator, to drop the psi down to zero and the vortex from the combustion chamber creates a siphon

at the nozzle to draw the fuel to be burned.  This design keeps the fuel pump from over sending fuel into the chamber after the unit has shut

down. Believe it or not, Telflex/Proheat had some smart engineers working for them at the time!

Nick-

[Bob Belter]

Ahoy, Bob,

The original fuel pump on the Proheat XL-900  //  1500 was a TERRIBLE piece of work!!!  I had the same critter in my Porsche Speedster MANY years ago, and almost burned it up!!!  I was astounded to find the same thing (defunct, of course) in the Proheat XL-1500 which I got to put into my Eagle.  I'd thought that those lousy pumps had been mercifully disposed of a long time ago.  I now have a X-45 installed in my -01 Eagle.

Yes, you were probably siphoning fuel to (not reliably) run the Proheat.  Also, the fuel pressure regulator has a very 'delicate' diaphram which can dry out and crack, giving you a fuel leak.  Good idea to replace it.

THe Proheat X-45 has an entirely different fuel pump / compressor unit which is excellent.

I agree with Nick that the Proheat guys are GOOD.  I'm very impessed with what a fine and reliable unit it is.

If you buy a new X-45 Proheat, much of the stuff on your old one will serve OK as spares.  I believe that even the controller will work, but without the 'soft start' of the X-45.

Enjoy  /s/  Bob 

[bobofthenorth]

Good to hear from you Bob - how's the roof on that Eagle where the tree hit it?

Happiness is a warm bus.  I woke up this morning -- late for a change.  I can remember waking up once in the night and listening to the furnace start.  Its still got the "wrong" fuel pump in it (a NAPA inline job that I happened to have in the bay).  I've been told that Teleflex has realized the error of their ways and changed to a pump that works.  I'll find out tomorrow if the local depot stocks one.  And it sounds like I might as well change the pressure regulator/diaphragm at the same time.  This is starting to remind me of my '86 GM 6.2 grenade.  After the 3rd engine I had so much money sunk into it that I would have had to own it for 100 years to come out even.  But, like I said, happiness is a warm bus.

Under the circumstances I can't resist this: the only explanation I can think of for such a poor design is some engineer must have thought it up.