truma heatstore water heater/autocruise tempo 2009

[coppack]

Recently noticed that whilst van is layed up on hook up water heater gets warm .Control switch is at off,Isolation switches at consumer unit are at off .Any suggestions please?.

[Derek Uzzell]

Welcome to the Out&AboutLive forums.

 

I'm guessing that your Autocruise Tempo has a Truma "Ultrastore Rapid" gas/230V 10 litres-capacity water boiler as shown here:

 

http://dealer.truma.com/_anweisungen/Truma-Katalog/pdf_verzeichnis/70_000/70020_85200.pdf

 

Logically, if your boiler is heating up when your Tempo is connected to a 230V power-supply, electrical power MUST be reaching the boiler. There's no chance of the boiler heating up spontaneously if no power to do this is available and (assuming there's no possibility of the boiler operating on gas while your motorhome is laid up) that means 230V power is somehow producing the heat.

 

I assume you empty your boiler of water prior to laying up the motorhome. Although Truma warns that an Ultrastore boiler must never be operated without water in it, the boiler has an over-temperature thermostat that should switch off the electrical heating element in such an instance. If your boiler is running empty on 230V, I suspect that the heating element would produce sufficient heat to slightly warm up the appliance before the over-temperature thermostat operates.

 

You say that the boiler's "control switch is at off,Isolation switches at consumer unit are at off", but the boiler is plainly getting heating power from somewhere. The first thing to do is to confirm that 230V power is present at the heater (which it really must be) and then work backwards.

 

In principle, there would need to be two 'faults' to allow the boiler to heat up - the consumer-unit isolation switch would need to allow 230V power through despite the switch being in the Off position and the boiler's control switch would need to function despite not being turned On.

 

A simple experiment would be to disconnect the hook-up supply to the motorhome for, say, 24 hours and then check that the boiler is cold. Then reconnect the hook-up supply and, 24 hours later, check if the boiler has warmed up. If it has warmed up, this will have proved that 230V power is reaching it despite the relevant switches being Off.

 

(If the boiler still manages to warm up with the hook-up supply disconnected, then Saint Rita (patron saint of impossible cases) may be interceding. ;-) )

[coppack]

Thanks Derek

Will implement your suggestions,& see how things go. *-)