Whale underfloor space heater

[RayS]

I've referred the problem to Whale but while waiting for their reply I wonder if anone has had a similar problem.
On turning the heater on using either of the electric settings, it runs normal for some minutes and then the fan slows down and the running becomes erratic, sometimes coming to a complete stop for a second or so. The same thing happens when using the Fan Only setting. The unit continues to run in this erratic manner until I can't stand it any longer and turn it off. I am not keen to try it on gas in this condition, but expect it would be the same.

I think I can eliminate something fouling the fan, as this would presumably apply from swith-on rather than after a few minutes (as something of this nature would also apply in the Fan only mode).

Weather conditions calm so rule out any odd back pressure conditions affecting the controls by differential pressure across the flue pipes, and such conditions cause lock out - no diagnostic lights appear)

My best guess is motor bearings or brushes (if the motor has any ?)

Still in warranty (just) so hopefully will get fixed free.

Any ideas ?

 

[RayS]

Looks like my best guesses were not very good. Whale responded promptly and sent me a training leaflet showing how to make basic fault finding tests. Quite useful, except I have an underloor unit difficult to access on a campsite with awning rigged etc.
They did also ask if I had tried the unit on gas, which I had not. As the idea of combustion with a fan seemingly about to fail did not seem very good.
However, with due care I did so and got the same result. Mnormal light up and running for about 3 minutes, the fan speed becomin erratic and dropping to nothing for a second or so before recovering to erratic slow running. So I switched off on the control knob. Unit entered the purge cycle correctly and seemingly at carrect fan speed, then shut down correctly.
Allowed it to cool and then tried again an electric and fan only settings. All worked correctly and have continued to do so for some hours and overnight !
So whatever caused the problem was seemingly removed by running a short time on gas. Mysterous. ( but quite a relief).

 

[ProfJohnL]

Hello Ray,

I can only speculate about the issue you have had, and the symptoms of the fan running apparently normally then after a while loosing speed and stopping sounds to me as through there may be a defective motor which is slowing or seizing as it warms up.

Looking at the Whale web site, I note their units have a significant resemblance to Propex units, and they seem to share the same model numbers!

See
http://www.propexheatsource.co.uk/heaters/hs2212-external-gas-mains-230v-heater

http://www.whalepumps.com/rv/siteFiles/resources/docs/resource-library/ah_cok_spaceheater_v1_may13.pdf
I have had some experience with the older Propex compact models, and I know this is a much older model than yours, I would comment the constructions was not of the highest quality, and I always wondered about their longevity in service.

 

[RayS]

Hello Prof. Thought this one might interest you. Your diagnosis is not far from my original, but I'm afraid that like mine it does not stand up as a faulty motor seems unlikely to cure itself, and since somehow clearing the fault I have run the unit for some 24 hours, more or less continuously.

In one way I'm quite happy as it's all well and working. However, there is the 'for how long ?' Question in my mind. I hate things suddenly going right for no good reason.

I agree the unit looks remarkably like the Propex unit with only cosmetic changes. Has Whale bought Propex ? ( or vice versa e,g Powrwheel and Truma)

I have and have had a variety of Whale products, inclding the dual fuel water heater on my current van, and would generally rate them above average in the caravan world ( although the submersible water pumps do not seem particularly long lived and are non repairable)

As standby we today bought a 400 watt x2 silica element heater complete with tilt safety switch for 9 euros (new) complete with multi page multi language instruction leaflet which could be condensed as 'Be careful - this gets hot' so shall not get cold on the way north back home.

I'll post any further developments.

 

[RayS]

Hello again Prof.
Just searched through Propex website and guess what, in 2008 Propex negotiated strategic partnership with Munster Simms Engineeriing ( aka, these days, Whale) so the basic design goes back quite a while. Wonder why it took so long to get used in caravans ?
Since the basic idea has been around for many years.

 

[ProfJohnL]

Hello Ray,

There are two reasons why this type of heater was not generally used in caravans.

The first was cost, they were generally about 2 to 3 x the price of the ubiquitous Carver/Truma convector heaters of their time. In every case the blown combustion models were far more expensive to produce and sell, and as we know the Caravan industry is very sensitive to cost prices after all it damaged profit margins.

Secondly then as now, the electrical requirements of running the fan were seen as unreasonable, especially at a time when EHU's were less common.

They were more often used in motorhomes and commercial vehicles like crew lorries and ambulances where space was more limited but there was an easily rechargeable battery with the engine.

Just to be clear Propex were not alone in producing this type of heater, Truma & Carver had blown combustion products. There were also manufacturers in the USA trying to make inroads into the UK & European markets, though their products were generally physically much larger and not suitable for our caravans etc.

 

[Hutch]

Ray, hope your keeping warm, looking into the fault, the propex unit says the fan is controlled by a microprosesser, ( wiggly amps) unit. Which gets its input from the thermostate to control the fan unit, two thoughts, if the thermostate, is a wire wound unit, grundgey contacts, but if your travelling back to UK maybe change of climate. And the blast of usage on gas has cleared any condensation on the circuit boards..
Hope yoir journeys is nice, tell us where you stay.
Hutch.

 

[RayS]

Thanks for replies. I think I can rule out condensation on the board as heater has been used nightly on electric at 1000w and should have had plenty of dry heat. Dry climate too.

Pleased to say Whale have taken problem seriously and are supplying new circuit board - FOC- (just in case) to be fitted at next service. Replies have been prompt and clear. Well done Whale.

As for location, Mojacar area of SE Spain, has some of highest sun hours in Sapin and around 4" rain a year.