Whale water heater and pump system... (1 Viewer)

[Clankie]

In 25 years of caravans and motorhomes I now have a very poor water system. It looks good elec/gas 750/1500w electric, 1250w gas and you can use both for quick recovery as it only contain 8.5 litres of water. My motorhome is Dec 15 and I have had problems since day one. The defect is that the system pressure drops and the pump kicks in to restore the pressure. The pressure relief valve is set at 3bar the system runs at 1.9bar. The relief valve constantly drips and this requires the pump to cut in. I have had a replacement relief valve and a replacement pump, no change whatsoever. The relief valve still drips. During the night the pump kicks in for less than a second which is s real pain in the bum!!! Whale suggested switch the pump off!! I can't believe it. The thermostat is fixed at 70 degrees C to eliminate bacteria, etc., I tried switching off the water heater at night but the pump still kicks in about every 5 minutes. None of the taps or toilet are leaking. Has anyone out there encountered this problem. Heater type Whale WH0802(B)
It's fine switching off pump at night then you forget and use loo, no water!! Not good in 2017.....

 

[SandraL]

Our last van had a pressure relief valve that dripped. We replaced the rubber seal. In normal circumstances it should not drip. But when heating water from cold , as the water heats and expands, the relief valve will open to relieve excess pressure. But once water is warm, no furthur expansion, no drips.
Unless pump is set to higher pressure than relief valve all should be good. First I would put pressure guage on system to find out what pressure it is at.
As you have changed valve already a pressure check seems next .

 

[Lenny HB]

You could try fitting an accumulator they are designed to stop the pump pulsing when taps are only turned on lightly but may not help if you have a dripping valve. No valve should drip so that needs sorting first.

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[Clankie]

Thanks both for responding, I agree with everything you say, I would be so pleased to have a pressure gauge in the system, then you can identify the problems. Whale have fitted an accumulator on the discharge, however it may be defective, that would make sense. I have a technical publication for the heater but nothing on the pump or accumulator. Elddis don't even mention a pump in their (very untechnical user manual) I am in Spain at present and will email Whale again regarding the accumulator, I think the pressure switch may be set too high and the the relief valve is lifting due to the system reaching 3bar. It the thermostat is fixed, I expect the pressure switch is the same for financial reasons, all very cheap!! The accumulator is only a plastic cylinder pre charged I would guess. Maybe when you start from dry the air in the cylinder is just compressed. It might have a spring loaded piston, I'll try to find out. Thanks again for reading and commenting.

 

[Lenny HB]

The cheaper accumulators are just a small plastic tank that hold a small amount of water to act as a buffer.
Pressure switches are normally adjustable and need setting up so the pump does not pulse. You have get a compromise over different voltages as your 12v supply will vary between 12v up to 14.4v when on EHU.

 

[dave newell]

First off I suggest everyone gets into the habit of turning off their water pump when its not needed, with a pressurised system this removes the possibility of the system emptying the tank into your cupboards if a pipe splits or joint fails. I saw this happen last year on an Autotrail on the local campsite, they phoned and left a message on the answering machine on Sunday afternoon but the earliest I could get to them was Monday afternoon. I was totally amazed that they hadn't thought to switch off the water pump even though they had a pipe under the island bed that had a pinhole in it so they had spent about 28 hours mopping it up and replacing towels under the bed every half hour or so. Switching the pump off also removes the possibility of that annoying burp in the night because system pressure has dropped slightly.

Secondly if the PRV is dripping then it is leaking and needs to be replaced again, either that or the pressure switch on the pump is set higher than the PRV opening pressure.

D.

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[two]

As the van temperature drops overnight the pressure in the water system will, too. If that's enough to bring the pump on, switching it off may be the simplest solution.
I think the drips may be from the dump valve. These can sometimes be seated better by fiddling with the actuator. Reducing the operating pressure would also help. On a few pressure switches you can adjust cut in and cut out pressures separately. An accumulator may not resolve that problem at all.

 

[Clankie]

Once again, thank you all for joining the discussion, Dave you are obviously in the trade, I've never had a pipe or joint go but I do hear what you say about pressurised systems. I do think without actually knowing what pressure the system is working at, that the cutout pressure is still too high, hence the PRV dripping. We are normally on a hookup and the voltage us always 1.5v higher than on the leisure battery voltage, so we may be increasing the cutout pressure. You are endorsing what Whale technical section suggested, switch it off at night if you are fed up with the bump! They said leave the power on, but I don't think that's a good idea. The first van we had, had micro switches on the taps, open tap pump start, but I guess that was a long time ago. Is this just a Whale problem, the Trauma system in my last van worked fine. Thanks again.

 

[two]

It's not unique to Whale but some systems might be more susceptible than others, just as some pumps will make more noise, depending on the method and location of installation.

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[Clankie]

Hi guys, latest on my Whale water system, apart from the dripping pressure relief valve which they claim is normal it is their suggestion that the suction and discharge valve block which Whale call the pump head is dejective, that is there may be dirt between the valves and seat allowing the HP side to leak back to the LP side allowing the internal pressure switch to allow the pump to kick in to restore the pressure. That does make sense as it is such a quick time interval. They are sending me a replacement pump head (valve block). They also said the suction filter should be cleaned every 30 working days, that's a new one on me. You are required to empty tank as no valves are fitted. Even if the filter is dirty it should stop the passage of grit into the valve block. I've looked at mine with a torch and it looks ok, it has a transparent cover. Looks like I'm going to carry more spares in future. I would strip it down to look for grit etc., but as I'm in Southern Spain if I have a problem I'm stuffed, as they say. @dave newell lvs

 

[pappajohn]

Turning the pump off at night and using the toilet. !!!
no problem on many RVs, the yanks have it covered with a secondary pump switch in the smallest room and even a third switch with the outdoor shower.

 

[Clankie]

Well the problem has come to a HEAD! Never mind valves, valve heads, pressure switches..... the inlet connector to the heater, 12mm pushfit to 3/8BSP was cracked and now has broken off in the the bottom of the heater body. You couldn't see the leak as it's about 2inches inside the heater casing. The heater is in a small cupboard at floor level and behind the pump etc. I had been looking for leaks but thus took so long to find. I removed the pump and Surge damper to get access, but trying to get to the final piece of pipe on the adaptor it finally parted. I though if was loose, not screwed right in at first but sadly it's now out of service. Always happens on a Saturday afternoon. I managed to purchase an east-out but it's just too small. All shops closed now till Monday. I have some Caravan/Motorhome dealers near Estepona but has anyone got knowledge of a mobile repair guy down thus way. I'm at La Bella Vista, nearest big town Estepona. May have to return to U.K. To get warranty repair. What a pain in the bum!!

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