# 747-2 hot water problem



## Raf (Nov 3, 2009)

On my newly purchased 2005 747-2 i have noticed that if i switch on hot water it takes quite a while for the hot water to come through. On cold settings it comes through straight away. If i turn it to on it splutters but nothing for quite a while. Also i have noticed that there is a button marked pumpe at the back of the motorhome near the alde heating controls. I have no idea what this is for. Can anyone help as i leave for France on tuesday. Thanks in advance.


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## dolcefarniente (Jan 2, 2012)

I don't know enough about your system to advise cause but don't turn on your water heater until you've bled all air from the hot water system after each tank filling. Depending on the size of your Burstner could the extra pump (my van has 2nd pump wiring etc but pump is an option) be to prime the system ? Provided you bleed it and it then holds pressure it shouldn't affect your trip.


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## Imbiber (May 11, 2007)

Hi Raf,

From memory the PUMPE in the rear is a switch for the central heating and works when your driving, so not connected to your hot water problem I don't think.

I do know that the hot water worked better on gas setting alone and not using the electric option....have you tried this?

We've sold our 747-2 but there are plenty of people on here that have them (they're great vans by the way) and I am sure that someone will be along shortly to offer further assistance.

Good Luck

Andy


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## Raf (Nov 3, 2009)

I have spoken to another 747 owner who tells me he had the same problem. It was the water going back down the pipe towards the tank. When i switch on the water its he air that comes out first and then the water follows a little while later. He fitted a non return valve in the water supply and says this fixed the problem.


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## Bubblehead (Mar 5, 2007)

Hi
You will get a little spluttering when you first open a tap. We have an 821 which is similar to yours water wise. When filling the fresh water tank you need to run each tap and shower in turn starting with the lowest one and turn each tap (mixer taps) from cold to hot until the spluttering stops.

Once the system is full and all the air out it should be OK. If you are still getting air in the system then you may have a duff pump or like already said water running back to the tank.

The heating is usually controlled by a 3 position slider switch when using EHU. The positions equate to 1, 2, and 3 Kw, position 1 is only any good for overnight hot water, 2 will heat a tank in about an hour, 3 in about 30 mins or so. be carful of using position 3 on sites with lots of EHU in damp conditions or those that are not 16 amp, you will trip.

The boiler and water system also have drain cocks for the hot and cold pipework which on our are located in the garage on the drivers side. use full for draining in winter and flushing through the boiler.

The Pumpe switch enables you to heat water / central heating whilst you drive using a pump in a belly locker (on ours) via a heat exchanger on the engine, it can also be used to warm the engine in very low temps overnight. To us it you need to switch the pump on and set the heater controls on the Alde control panel. We dont tend to use ours as it seems to drain the hab battery whilst on the move for some reason, not good if your not going to be on EHU.

Hope this helps, enjoy your holiday


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