Replacing Truma Ultraflow Surge Damper Pressure Switch

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Aug 11, 2005
My Coachman VIP 2008/9 has a Truma Ultraflow Surge Damper with Pressure Switch that I suspect is faulty. After using the taps the pump continues to run. I've adjusted it as per the manufacturers instructions, but even with the screw fully set to 'minus' the external pump still runs. I've checked the o rings on the pump connection, straightened the pipe in the aquaroll, tightened the filter lid and replaced it's o ring, all have made no difference! Switching the pump off and back on at the main switch will often stop the pump, however the next time any tap is used the pump runs continuously again.

I'm aware the Truma Ultraflow Surge Dampers are no longer available, so am considering upgrading the set-up to a Whale Inline Pressure Switch with separate Whale Surge Damper. My question specifically relates to the wiring, connection of the replacement pressure switch, as it's clearly not a straight swap. On the new switch are the two spade connectors both positive? If so would simply connecting together the negatives of my existing setup and connecting the two positives to the new Inline Pressure Switch then mean the pump is then switched via the positive?

Jan 9, 2018
Hi @Freelander2

Please feel free to contact our Customer Support Team who will do all they can to assist you with your query. You can call them on 0345 9090 911 or email Alternatively, please send me the best number to get you on and I will get one of our team to give you a call.

Best wishes,
Aug 11, 2005
I thought I'd follow this thread up with the results of the upgrade, in case it helps anyone out in the future with a similar issue. Whale Technical Support were very helpful, first phoning me, then emailing their recommended part numbers and a circuit diagram. Whilst obviously they couldn't give exact advice on adapting my existing wiring, I had enough useful info to do the conversion.

The new Whale Pressure Switch and separate Whale Surge Damper were fairly straightforward to fit, with the purchase of some extra water pipe and a couple of elbow joints. The battery + & pump + from the old unit (after changing the spade connectors) connected to the new pressure switch. The negative battery - & pump - wires were simply jointed together.

Technically at this point the pump worked exactly as it should, however connecting the three negatives together meant the red 'pump running' warning light in the switch on the main control panel was permanently illuminated. The third black negative was clearly for this led, not a big issue but not ideal. Rather than trace out the original wiring, I fitted a 22mm 12 volt blue led, wired to the pump + on the pressure switch and the battery - connection and now regard the original red switch led as 'pump power on' but not running!

The end result is perfectly running water, a pump that switches on and off quickly, with 'pump running' led that is visible wherever you are in the van, so for me an upgrade on the original factory spec.


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Mar 14, 2005
Hi, a newbie here having the same Truma problems
If I can be cheeky how much was the new equipment from Whale?

Whales prices are easily found by googling whale water systems. To replace teh Truma unit, you will need a whale pressure switch and surge damper , and may be some water pipe and fittings.

And me - just arrive for a 10 day break and this unit has failed, any help or advise urgently required please.

It will depend on what's stopped working, PLease give us a few more details and the sysmptoms. Otherwise if your not confident in investigating and making repairs you will be best to call and AWS mobile engineer to come and help.
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