HWH system alarm coming on

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HWH system alarm coming on

February 22, 2020, 10:05:46 pm

Today while driving an alarm came on and level system warning light came on and was some time on solid and some times intermittent. It would do that for a while and then stop and then start up again. The alarm was annoying and every thing seemed fine in the suspension.

Re: HWH system alarm coming on

Reply #1 – February 22, 2020, 10:32:21 pm

Was air pressure normal?

Did "Travel Light" go out while alarm was squawking?

In "Travel Mode" the only thing that should trigger a alarm is low air pressure ( <80 psi ) at the rear 6-pack manifold pressure switch.

Re: HWH system alarm coming on

Reply #2 – February 23, 2020, 12:11:31 am

The travel light went out and the air pressure gauges were up. I have a slow leak that leaks down to 60 lbs and then holds. The leak
is not in the air bags as a couple of days ago I lifted the coach up and put the blocks in and it stayed up for 24 hours and then I
just pulled the blocks out.

Re: HWH system alarm coming on

Reply #3 – February 23, 2020, 08:20:10 am

Symptoms suggest a false low pressure signal being sent from the rear 6-pack manifold pressure switch to the HWH control box.

Could be a failed pressure sensor, or a bad wiring connection at the sensor (loose, corroded or broken wire).

See post linked below to a discussion of the pressure switch setup on the 6-pack manifolds:

6 pack rebuild (Reply #3)

If you decide to try a new pressure switch, post linked below has some part numbers:

6 pack rebuild (Reply #11)

Re: HWH system alarm coming on

Reply #4 – February 23, 2020, 09:37:53 am

Can alarm mean low hydraulic fluid level, or rv out of level, like when going over a driveway or raised railroad track?

Re: HWH system alarm coming on

Reply #5 – February 23, 2020, 09:46:22 am

Quote from: Jack L – February 23, 2020, 09:37:53 am

Can alarm mean low hydraulic fluid level, or rv out of level, like when going over a driveway or raised railroad track?

The audible alarm can be triggered by myriad problems in the coach. It is a "multi-purpose" attention getter.

The OP asked specifically about: audible alarm PLUS level system warning light PLUS travel light out, whilst air pressure was normal.

IMO, that combination points to a specific problem.

Re: HWH system alarm coming on

Reply #6 – February 23, 2020, 10:29:07 am

We are 400 miles from home, dry camping at Rogers Pass, ski touring and will be here for 2 weeks. I guess the pressure sensors
are under the coach.

Re: HWH system alarm coming on

Reply #7 – February 23, 2020, 10:34:07 am

Quote from: oldguy – February 23, 2020, 10:29:07 am

I guess the pressure sensors are under the coach.

Correct. The rear pressure switch is on the rear 6-pack manifold, mounted to the frame, up above the axle. May be visible when looking in one of your rear-most storage bay doors, kinda above and behind the frame-mounted fuel filter?

Re: HWH system alarm coming on

Reply #8 – February 23, 2020, 01:48:40 pm

Sometimes I have the same problem. I push the "Raise butteon" for a second and everything is good again. I have to repeat it from time to time, mostely after a period of parking.

Re: HWH system alarm coming on

Reply #9 – February 23, 2020, 02:14:09 pm

Reach in there and unplug and replug it in.
May help.
Also look at the wiring.
If that doesn't fix it it's probably the switch.

Re: HWH system alarm coming on

Reply #10 – February 23, 2020, 08:16:55 pm

I will crawl under the coach when I move the coach, hopefully not until Saturday when we go to town to by food and dump, to
see what I can see. Chuck I have read your links and thanks for the information and I will keep you posted.

Re: HWH system alarm coming on

Reply #11 – February 23, 2020, 08:37:01 pm

Last fall I had my front ride height valve fail and had the same symptoms you have. I figured out what it was as I bounced off my front tires while driving. Level system alarm, travel light going on and off while driving, etc. I had air pressure but the ride height valve failed. If it fails completely you could be on the side of the road, so check it out carefully. I figured it out stopped on level ground and went outside with the coach running and saw my front wheels almost having the coach sitting on them.

Hope you get this resolved. The ride height valves are common truck parts.

Re: HWH system alarm coming on

Reply #12 – February 27, 2020, 12:05:19 am

Just and up date. We had to drive to Revelstoke to sort out a water leak problem and driving down it was dry and no
level system alarm and coming back it was wet and the alarm came on. I have been under the coach and the front I see
the air pressure sensors and the rear I couldn't see them. I would just as soon fix it when home as I'm not fussy about laying in
the snow on my back trying to sort it out. Did enough of that when working.

Re: HWH system alarm coming on

Reply #13 – February 27, 2020, 08:36:02 am

Suggests that water might be getting somewhere it's not supposed to be. Might be shorting out the contacts on the rear HWH pressure switch...simulating a "low air pressure" condition. If you are lucky could be a easy fix.

Link below to a thread with photos of rear pressure switch (2002 U270). Probably similar to the setup on your coach.

Another air leak this time at rear six pack pressure switch

Re: HWH system alarm coming on

Reply #14 – March 01, 2020, 07:47:10 pm

Drove to town yesterday and hadn't put in my hearing aids and that fixed the alarm. So when we head for home next Saturday
afternoon I will leave my hearing aids out and as I can't hear the alarm I won't go nuts.

Re: HWH system alarm coming on

Reply #15 – March 11, 2020, 10:48:32 pm

I have removed the front pressure switches and they are Hubbs switches and they have NO on them which I took for normally open
but they both show closed circuit and at 10 lbs they show resistance. The NO could be ON depending on the way I read it. I haven't found a pressure switch on the rear manifold yet. I will look again tomorrow.

Re: HWH system alarm coming on

Reply #16 – March 11, 2020, 10:57:32 pm

Quote from: oldguy – March 11, 2020, 10:48:32 pm

I have removed the front pressure switches and they are Hubbs switches and they have NO on them which I took for normally open
but they both show closed circuit and at 10 lbs they show resistance.

Link below to the replacement switches I used when I rebuilt my front 6-pack manifold. They should be NC (normally closed).

Stewart Warner-Stewart Warner Hobbs Pressure Switch 10 PSI Normally Closed 2...

Re: HWH system alarm coming on

Reply #17 – March 12, 2020, 10:53:41 am

That's how they are reading as normally closed. I will check them with a head light bulb this morning.

Re: HWH system alarm coming on

Reply #18 – March 12, 2020, 01:15:33 pm

Using a test light to test the 2 front sensors one of the sensors the test light would go very dim but not out so that one is failing. I found the rear one. My problem was I was looking for a normal looking pressure switch not a rectangular box. Chuck thanks for the part number.

Re: HWH system alarm coming on

Reply #19 – March 12, 2020, 01:37:32 pm

The front 10 psi switches don't have anything to do with the alarm.
They are there to stop one side from continuing down after the other side bottoms out ( and it sees less than 10 psi ) to prevent twisting the coach.

Re: HWH system alarm coming on

Reply #20 – March 12, 2020, 01:43:56 pm

Thanks John so I will check out the rear.

Re: HWH system alarm coming on

Reply #21 – March 12, 2020, 06:50:44 pm

Quote from: oldguy – February 22, 2020, 10:05:46 pm

Today while driving an alarm came on and level system warning light came on and was some time on solid and some times intermittent. It would do that for a while and then stop and then start up again. The alarm was annoying and every thing seemed fine in the suspension.

You may consider installing a switch at the dash to turn off the chime when not wanted. It freaks our cat when airing up at start, so I turn it off till I reach required air pressure.

I also used it, when I had a bad pressure switch, while driving home from Az. a few years ago.
CW

Re: HWH system alarm coming on

Reply #22 – March 12, 2020, 09:27:38 pm

The alarm only bothers me if my hearing aids on in. I checked the rear sensor this afternoon and it works fine.

Re: HWH system alarm coming on

Reply #23 – March 12, 2020, 10:49:07 pm

I have the same problem with my coach it works just like you explain I left Canada in the cold as soon as I got in a warmer climate it never happened back again at first I Figure it was because I was driving in the Highwinds and the coach was leaning hard to one side but as soon as the weather warmed up it never Occurred back again rain or dry

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