aztec electric boiler in lockdown

misscatty01 · 2 May 2009

hi, i have an 12kw aztec electric boiler that keeps going into lockdown, the only way to get it to run is to switch the electricity supply off then on again but we have to do this virtually every time we want heating/hot water. there is a megaflo tank and water was running constantly out of the overflow we've had a couple of different plumbers out to look at it, one replaced some leaking valves either side of the pump the other repaired some wiring in the boiler and changed the TP valve on the megaflo tank. The overflow of water has stopped but the boiler still isnt working properly. When it runs either the boiler or the pump (im not sure which) make a loud whirring noise for a few seconds then it either quietens down and runs or goes into lock down.

obviously we are going to have to get someone back out again but i would like to know what the problem could be as the people we have had seem confused by the fact that it is electric.

many thanks for any advice

Cat

Slugbabydotcom · 2 May 2009

Cant be certain without seeing it but it does sound like a dodgy pump.

aztec12kw · 20 May 2009

Hi
Your problem is almost certainly the 'start up' circuit.
The large black capacitor (marked C2) which is next to the transformer, probably has a domed shape to it's top instead of being flat like the others. This means it's blown and needs changing. Can be changed by someone who knows what they're doing without having to take the pcb board off it's mounts. It's done by cutting the capacitor in half with electrical cutters, then cleaning away all the inside of the capacitor and soldering a new one to the old one's pins. Note that this capacitor must be fitted the right way round, the white patch on the pcb is the negative side and matches with the grey band on the capacitor.
Otherwise it's a new pcb at somewhere near £300.
Good luck

AlisonMitchell · 10 Aug 2011

Hi Cat

I too have an Aztec Trianco 12 kw electric boiler as well as a Potterton Gold 12 kw electric boiler with a 150 ml cylinder and have experienced same problems. Mine resulted from dodgy wiring by a very dodgy builder. I have been told that the faulty wiring has resulted in both circuit boards being blown through running noisily and constantly for 24 hours.

I am not sure how much it will cost to replace both circuit boards.

Hope this helps!

mointainwalker · 11 Aug 2011

Hope this helps!

As she posted two years ago, probably not

Agile · 11 Aug 2011

AlisonMitchell said:
Hi Cat

I too have an Aztec Trianco 12 kw electric boiler as well as a Potterton Gold 12 kw electric boiler with a 150 ml cylinder and have experienced same problems. Mine resulted from dodgy wiring by a very dodgy builder. I have been told that the faulty wiring has resulted in both circuit boards being blown through running noisily and constantly for 24 hours.

I am not sure how much it will cost to replace both circuit boards.

Hope this helps!

150 ml is the size of a small glass of wine!

Must have been a very dodgy builder!

Circuit boards can be up to £200 each and a labour charge will be needed to fit them.

But first the actual fault needs to be correctly diagnosed. Because these are electric boilers the number of engineers being comfortable with them will be lower.

Tony

AlisonMitchell · 11 Aug 2011

Agile said:
AlisonMitchell said:

Hi Cat

I too have an Aztec Trianco 12 kw electric boiler as well as a Potterton Gold 12 kw electric boiler with a 150 ml cylinder and have experienced same problems. Mine resulted from dodgy wiring by a very dodgy builder. I have been told that the faulty wiring has resulted in both circuit boards being blown through running noisily and constantly for 24 hours.

I am not sure how much it will cost to replace both circuit boards.

Hope this helps!

Click to expand...

150 ml is the size of a small glass of wine!

I am laughing, I think I meant 150 litre?

Thanks for your advice. I am now wondering if it is the PCB. I put on the central heating this evening and there was no noise or water running but when I switched off the heating and moved to hot water only the noise was there again and running constantly. It does seem strange that the two 12 kw boilers seem to have blown at the same time. One is an Aztec classic and the other is a Potterton Gold. I don't have the manufacturer details as the cowboy builder did not provide them.

Must have been a very dodgy builder!

Circuit boards can be up to £200 each and a labour charge will be needed to fit them.

But first the actual fault needs to be correctly diagnosed. Because these are electric boilers the number of engineers being comfortable with them will be lower.

Tony

mysteryman · 12 Aug 2011

Makes you wonder what is the point in heating a cylinder by a separate electric boiler? Why not just use an immersion heater?

AlisonMitchell · 12 Aug 2011

mysteryman said:
Makes you wonder what is the point in heating a cylinder by a separate electric boiler? Why not just use an immersion heater?

I take your point. For some strange reason the cowboy builder installed two 12 kw electric boilers for a 4 bed detached house. One has now been disconnected but the central heating and hot water run off the same boiler and attached to a cylinder.

Could I just get an immerser heater instead of heating the water via an electric boiler? However, this still doesn't sort the problem of the heating system running 24 hours due to a problem with the boiler but thanks so much for your advice - much appreciated!

tomatokinglover · 11 Mar 2014

Hi
Your problem is almost certainly the 'start up' circuit.
The large black capacitor (marked C2) which is next to the transformer, probably has a domed shape to it's top instead of being flat like the others. This means it's blown and needs changing. Can be changed by someone who knows what they're doing without having to take the pcb board off it's mounts. It's done by cutting the capacitor in half with electrical cutters, then cleaning away all the inside of the capacitor and soldering a new one to the old one's pins. Note that this capacitor must be fitted the right way round, the white patch on the pcb is the negative side and matches with the grey band on the capacitor.
Otherwise it's a new pcb at somewhere near £300.
Good luck

Hi Aztec12KW - any chance you can remember the specification of the capacitor? Mine has just blown and I can't make out the writing on it.

many thanks

Tomatokinglover

diynot

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

aztec electric boiler in lockdown

mysteryman

Similar threads