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Topic: Engine heat switch for aqua hot (Read 1005 times) previous topic - next topic

Engine heat switch for aqua hot

When I flip the engine heat button the AH makes a funny noise. Almost like a fan not being able to turn. I left it on for a minute but I switched it off.
Is that sound normal.
First time I did it.
Also what is the 115vac switch for?
Rick & MJ Berry
1998 U320 40'
Ohio

Re: Engine heat switch for aqua hot

Reply #1 –
Quote from: 18360 –
1. When I flip the engine heat button the AH makes a funny noise. Almost like a fan not being able to turn.
Is that sound normal.
2. Also what is the 115vac switch for?

Rick,

1. Sounds like you may have a zone circulating pump failing that is for the engine heat loop.
2. When that switch is on it powers an 120VAC heating element it the A/H unit. This can be used with the diesel side or independent. If only on 120 you will have limited heat.

Mike

Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Engine heat switch for aqua hot

Reply #2 –
If you haven't been using the engine heat switch, I'd go ahead and flip it on.  It only controls a valve that allows engine coolant to circulate through the A-H.  You need to have either the diesel or electric switch on to actually heat the coolant.  You can feel the engine head or use an IR gun to confirm the valve did open.
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Engine heat switch for aqua hot

Reply #3 –
The valve Brett referred to is actually the Engine Preheat Pump.  Once turned on it circulates engine coolant from the engine, thru the heater and back to the engine.

This switch is only on for the hour or two to maybe overnight when starting the engine in very cold conditions.

With the preheat switch off and main engine running, the main engine water pump circulates hot engine coolant through this loop heating the Aqua Hot coolant.

Hope this helps
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Engine heat switch for aqua hot

Reply #4 –
At what temperature should you use this. It's 31;degrees here.
Rick & MJ Berry
1998 U320 40'
Ohio

Re: Engine heat switch for aqua hot

Reply #5 –
Quote from: 18360 –
At what temperature should you use this. It's 31;degrees here.

It certainly wouldn't hurt to turn it on at that temperature, but you don't necessarily have to. I've started our Cummins at temperatures in the mid-20s without preheating without any problem.
David and Carolyn Osborn
1995 U320C SE 40' Build 4726 Feb 1995
FMCA 147762
Motorcade 17186

Re: Engine heat switch for aqua hot

Reply #6 –
I use mine any time it's below 40 deg. Sure doesn't hurt to have a warm eng when starting!
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Engine heat switch for aqua hot

Reply #7 –
So I did preheat the engine and it did start better than the last few times when I started it in similar cold temps (it always started
right away but after a few seconds after firing up it seemed like it was going to stall; and that lasted only a couple of seconds).


Thanks for the help
Rick & MJ Berry
1998 U320 40'
Ohio

Re: Engine heat switch for aqua hot

Reply #8 –
Quote from: 18360 –
So I did preheat the engine and it did start better than the last few times when I started it in similar cold temps (it always started
right away but after a few seconds after firing up it seemed like it was going to stall; and that lasted only a couple of seconds).


Thanks for the help

Fuel lines and/or Winn
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Engine heat switch for aqua hot

Reply #9 –
Rick, starting any engine warm is better than cold starts-- Yes they will start cold but until the oil is warm it don't flow through the filter as easily.  I heat my engine year around--always warm start, Just me!
Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: Engine heat switch for aqua hot

Reply #10 –
I was told one time to be sure and turn the preheat switch off before starting the engine. Did not ask why.
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Lynn & Marilyn Sickel
Tollville, AR
1997  U320  40'
2021 Chevrolet Silverado pickup
Motorcader  17257

Re: Engine heat switch for aqua hot

Reply #11 –
Lynn, I assumed( you know what that gets you) that the water pump may be pushing water in the opposite direction as the aqua hot
pump, but have not been able to verify that.-- BTY I was told the same thing plus turn off block heater!
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: Engine heat switch for aqua hot

Reply #12 –
Yes, make sure to turn off the block heater before starting the engine.  It will burn out and be expensive to replace.  Don't ask how I know.
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R