Help! What am I missing Potterton Suprima with a new board

[gaz_]

DIYer here and this has been annoying me now for a few days.

It all started with the boiler (Potterton Suprima with a new board) in the kitchen just clicking on and off failing to light. A few minutes with the meter and I speculated that there was a pump motor problem especially since spinning the pump by hand sometimes got the system running. So off I go and buy a new pump.

The system magically kept running though so I left it alone for the day until I noticed that I had hot water but no heat, when there was a call for heat there was no activity from the boiler. My initial thought was that I'd disconnected something with the meter but now I was making myself problems. Time to call the "Professional" heating guys

"Professional" comes out and looks at the system, I mean just looked and says your pump is bad you have another one so just replace it and it'll fix everything, ask are you sure everything, I have two sets of symptoms? He says yeah and promptly leaves, 10 minute visit. I'm complaining about that to the company.

So I change the pump, no joy, and then notice that the mid flow valve isn't changing position for hot water. I move it by hand, low and behold the heat system now exhibits the same problem as the hot water. My "professional" didn't bother to check that one?

Pull the system apart and find that despite voltage the motor won't move even on its own so another quick trip out and get a new motor, fit it, no joy.

Now I notice that the new motor says it is 230v and the terminals feeding it only read about 90v which is odd but might explain the motor not working.

At the moment I feel like I'm throwing good money after bad because I can't seem to track down what this intermittent issue is, some days the boiler starts, others like today nothing. My gut is saying boiler control board but that is an expensive "trial"

Does anyone have any tips to help me trouble shoot this?

Things I've done so far are cleaned the igniter area on the boiler

Change the pump
Change the actuator on the valve
Reset everything repeatedly
Checked the wiring as best I can with a meter
Changed the thermostat on the boiler since the old one just spun around​

Any help would be great.

Thanks,

Gary

 

[joni os]

Disconnect boiler and pump live , at wiring centre. Check your controls function correctly ie. 240 volts at appropriate terminal. Reconnect pump and ensure this runs when calling for heat or hot water. Finally reconnect boiler. The controls do not need the boiler connected to function properly. The pump and boiler are in parallel circuit,if one runs correctly so should the other.

 

[gaz_]

OK, did that and there is no life in the system at all, could a problem with the mid flow valve be confusing the system?

I checked the controlled and there is still switched power on the terminals there

 

[Last Plumber]

Have you checked that you have live neutral and earth and all are reading correctly ?
The 90V thing needs addressing. How did you read that voltage and on which terminals

 

[Last Plumber]

Have you checked that you have live neutral and earth and all are reading correctly ?
The 90V thing needs addressing. How did you read that voltage and on which terminals

 

[gaz_]

More fiddling this morning, I can't get the 90v again, I wonder whether I was reading that through some coating on the board. This morning it all reads 240v.

I just tried completely disconnecting the valve actuator and that doesn't in anyway affect the click on click off on the boiler.

With the actuator apart I can feel the motor trying to move but no actual movement. It seems to be a separate problem from the boiler but still intriguing.

 

[Last Plumber]

What are you testing ?
L-E
L-N
As far as the boiler goes, you need to be gas safe registered to work on that.

The other things can all be tested and proved, there is no reason to swap and change parts just to find out what's wrong.

Not only that but by fiddling about you are making it worse for the heating engineer who eventually will have to fix it and not know what you have altered.

Please get a recommended gas safe heating engineer to sort the problem for you. To be honest it sounds like a straight forward fault finding exercise

 

[Last Plumber]

What are you testing ?
L-E
L-N
As far as the boiler goes, you need to be gas safe registered to work on that.

The other things can all be tested and proved, there is no reason to swap and change parts just to find out what's wrong.

Not only that but by fiddling about you are making it worse for the heating engineer who eventually will have to fix it and not know what you have altered.

Please get a recommended gas safe heating engineer to sort the problem for you. To be honest it sounds like a straight forward fault finding exercise

 

[gaz_]

Indeed, that is why I stopped Thursday, got a heating engineer out Friday who was useless and left me with a weekend of no heat and hot water.

I'm happy to look at the electrical, I'm not going near the gas side of things.

I guess that is what I'm asking... what do I test? The programmable controller is creating a solid circuit L-N for both hot water and heat. The boiler clicks on and off and the motorised value isn't motorised despite a good voltage. I will call a new engineer Monday but that doesn't help me after Friday's incident.

Maybe the question is, is there a flow chart out there to diagnose a normal system, perhaps something trainee engineers have put together that I can work through?

 

[magicno1]

This is a straight forward issue to sort! Get an experienced engineer who is gas safe and they will sort it. If you don't know what you are testing for and know how these systems are wired and should work leave it alone. I for one will not if the customer has fiddled! Simple that's why we are trained and spend our hard earned money to be LEGALLY allowed to do so!

 

[Rickster123]

Good advice given above.