Carver Rapide water heater

[Castle2108]

Can anoyne help with some advice? U have a Carver Rapide water heater, working on mains electric fine, The Gas won't work, the red light comes on straight away on the control panel, I have tried purging the gas serveral times to allow for air, The unit has been away amd completely refurbished with new parts and tested and sent back working, Theres not clicking or spark when trying the switch. Dose or has anyone else experianced this? Im guessing theres some kind of eletrical fault between the switch/control panel amd the burner telling it not to spark or release gas?.
If the burner is undone the gas goes as far as the burner so know that gas is getting to the burner. Any help appreciated.

 

[ProfJohnL]

Hello Castle,
Does your Cascade use a black round DIN plug connector for the control loom between the switch and the burner module? The cable only has 5 pins but some sockets had 7 pins. Check it hasn't been forced into the wall switch or the burner module one pin out of proper alignment.

I was once called with a similar problem by someone in Long Melford. I suggested trying the Din Plug, and they swore blind it wasn't the problem. Our Marketing Director asked me to go and investigate.
150 miles and 3.5 hours later problem was din plug been forced in by the caravan manufacture, Fixed in less than a minute.

If that isn't the problem then it seems its most likely the Burner Control Module is faulty.

 

[Castle2108]

Thank you I will check but its the flat pin not a Din one obviously I have checked the flat one serveral times but not yet the switch end, I will have another look again tomorrow though. Highly annoying as the new actual burner unit had been away had a complete refurbishment and new parts and been tested fully working with 12 months warranty before coming back. When you say Burner control module do you refer to the switch or the one that releases gas and send the spark?

 

[ProfJohnL]

The BCM is the part in the heater not the wall switch.

My diagnosis is based on your comment that the appliance went straight to red. I'm assuming it didn't display green or yellow at all.

I would have a word with the supplier who refurbished the heater. Under the Consumer Rights Act you are not necessarily limited to just a 12 month guarantee.

 

[Castle2108]

Thanks It was green amber amd red all at the same tome and was prior to going for the repair, the burner unit has been fully refurbished and tested before coming back that however dosent mean theres not a problem with it but I fear it's elsewhere. There is definitely gas getting as far as the unit as if not done up tight you can hear and smell it. However we have no spark or gas after unit is fully fitted and the control panel is lihht like a xmas teee.

 

[gary]

Reading though Im confused! When you say red comes on straight away, do you mean instantly with the green? Or after 8-10seconds?

 

[ProfJohnL]

It seems we have been misled, all three lights are apparently illuminating not just the red!

I repeat I think you should contact the supplier who refurbished the burner.

 

[Castle2108]

exactly yhe same time

 

[gary]

All three lights together is almost certainly water ingress on the electronics inside the black box.

 

[Castle2108]

thanks however this was sent for repair and sent back working its since not been exposed, its been suggested now its an earth issue between switch and bcu which is next step

 

[ProfJohnL]

IF teh heater has been damaged by frost, it can allow water to drip from teh main tank onto the BCU.

You maybe best getting a qualified caravan engineer to inspect and advise first hand.

 

[Castle2108]

Thank you I have now organised that, There is definitely an eletrical fault I shall keep you posted.

 

[Castle2108]

So a quick update, Universal Caravan repairs came out today and still baffled, 3 lights on everytime. We have tried a replacement switch another burner unit and parallel checking of wires from switch to BCU and still 3 lights every time the feed from the switch to the unit plug is reading at 12.9volts. Has anyone please got any other ideas?

 

[ProfJohnL]

Hello Castle,
If I understand correctly, your fitter has tried replacing ,
the BCU,
the wall switch
and the multicore cable between the BCU and wall switch,, and each change of item the exact same effect was noted of red amber and green lights ALL illuminated at exactly the same time?

If this is the case then , then it is a very baffling problem. All the components that are involved with the control of the gas side of the heater are entirely contained in those three items. I assume your fitter could vouch for the working condition of the spares he/she tried? So what is left is something external to the heater, and that would have to be the 12V power supply.

Did the fitter confirm the measured 12.9 voltage was DC with no AC component?

Was the caravans 12V power supply just from your caravan battery?
Was it caravan battery with charger being powered by 230V mains?
Was the caravan battery disconnected and you were just using the caravans battery charger to provide 12V?

My suspicion is if the power supply has any AC component or ripple, the troughs in the ripple may be low enough to turn the control circuit off and the peaks will try to turn it on at mains frequency or twice mains frequency if the charger is full wave rectified. This could fool the circuit and cause it to show all three lights at the same time.

Edit.. How old is your caravan, and what make &model as that might give a clue to the type of charger or power supply you have .

 

[Castle2108]

So after everything it turns out the switch had had it and despite the engineer try another his was gone too. A new switch from ebay and all is fine.

 

[gary]

Well! that's a new one on me??
I've fixed many dozen switches but never for this! Can I take it this faulty switch had Carver written on it and not just plain?

 

[Castle2108]

yes both switches tried previous had carver on them

 

[gary]

Thanks, it was just a thought as i don't recognise the fault being switch related