Pulsacoil A-Class, APA4180 Fault

Hi,

I have a Pulsacoil A-Class APA4180 in my flat which has stopped giving me hot water. It's not freezing cold, but nowhere near hot and is consistently this temperature. I've had this happen a few times in the past accompanied by the medium flashing red light, but I could always turn the boiler off and on again and it would work again as normal. However, on this occasion there is no flashing red light and that trick no longer works. When I turn it on the pump seems to fire up and get warm (nothing else seems to) and I hear relays clicking.

I have checked the display under the front panel - the status screen shows all the lights I would expect to be on according to the manual. There are three instances of error code 56 and three of 37. However, I have checked the resistance of both immersion heaters and I get ~19 Ohms which I believe is about right for it to be working properly...

Has anyone got any ideas of what the problem might be, or anything else I can check to further diagnose the problem?

Any help is much appreciated!

Many thanks,

Ben

Done the usual and checked the F& E tank?
If not heating on off peak, try boost.
Is the unit hot? Feel big fat pipe on the top.
Mike

Hi Mike,

Thanks for the reply.
I've checked the tank on the top and that's fully topped up. Unfortunately the boost button doesn't seem to do anything (and hasn't done for the whole time I'v lived in the flat). The only thing I've found that gets hot is the pump...

Hi

I had a similar problem - an engineer isolated the fault to the control board and also one of the elements. It seems your elements are ok though so maybe worth replacing the board which is very easy to do?
I am certainly no expert as you can see from my question!!.....To drain the cylinder (I am going to have a go at changing the elements myself) I presume the vent will need to be opened. Do you do this by emptying the water below the outlet in the F & E tank as there does not seem to be any other vents to open?

Thanks for any help anyone can give me.

Rob

speedalini wrote:Hi,

I have a Pulsacoil A-Class APA4180 in my flat which has stopped giving me hot water. It's not freezing cold, but nowhere near hot and is consistently this temperature. I've had this happen a few times in the past accompanied by the medium flashing red light, but I could always turn the boiler off and on again and it would work again as normal. However, on this occasion there is no flashing red light and that trick no longer works. When I turn it on the pump seems to fire up and get warm (nothing else seems to) and I hear relays clicking.

I have checked the display under the front panel - the status screen shows all the lights I would expect to be on according to the manual. There are three instances of error code 56 and three of 37. However, I have checked the resistance of both immersion heaters and I get ~19 Ohms which I believe is about right for it to be working properly...

Has anyone got any ideas of what the problem might be, or anything else I can check to further diagnose the problem?

Any help is much appreciated!

Many thanks

Ben

Your 56 error is a PCB fault, but try first 37 error( this is an open over heat sensor fault). I would fit new store sensors ( one twin GT199, and two single GT198) and also have a close look on the relay, may the OP relay also need new.
hope this helps
Mario

Rob Coll wrote:Hi

I had a similar problem - an engineer isolated the fault to the control board and also one of the elements. It seems your elements are ok though so maybe worth replacing the board which is very easy to do?
I am certainly no expert as you can see from my question!!.....To drain the cylinder (I am going to have a go at changing the elements myself) I presume the vent will need to be opened. Do you do this by emptying the water below the outlet in the F & E tank as there does not seem to be any other vents to open?

Thanks for any help anyone can give me.

Rob

The Pulsacoil is a open vented Cylinder, the 22mm pipe from the boiler to the Gray top tank ( F & E) is your vent pipe, so you not have to open any extra valve to vent. Some Pulsacoil drains are blocked or sledged up, this can course a long drain down time ( from 160 L to 225 L water in the Pulsacoil). Also some Immersion are very solid fitted ( some honks in the factory was using glue seal to fit them). A good bock spanner is required, and of course the fitting Immersion (XB083). Expect this job will take 2,5 to 3,5 h all in and refilled and don't verged to put inhibitor in the new water filling .
hope this helps
Mario

Thanks very much Mario you've been a great help!
As you said once I stuck a metal wire up into the drainage tap to dislodge all the crud it drained fine but took a while.
The elements were a really pain to get off (as you said they would be) but I bought a decent immersion spanner, not the cheap thin one and with some WD-40 and a bit of heave they came off.
Ive replaced the elements and filled the tank up with some inhibitor and put some plumbers blue around the threads so fingers crossed.

Thanks again!

Hi Rob,

Read about the work you did, congrats! Now you have installed the elements just make sure you use your system correctly. I would recommend you keep copies of the following listed below and have a quick read when you get a chance:

Pulsacoil Official Manuals: Pulsacoil A Class Manual
Self check Pulsacoil Mini Guide: Pulsacoil A Class

I hope these help you and well done again.