help need halstead ace boiler

[gas1981]

Hello

I am currently trying to help a customer with her boiler, the gas council number is 4733316 (halstead ace, combination boiler)

At the moment is all off, no heating or hot water.
The fan does not work, but the pump works.

After investigating I found that it is not the over heat stat, or the flow switches, the air pressure switch is also okay.

I discovered that the pump live was showing as neutral, and the neutral was live, at this point I though it was a neutral fault so I had a look at the polarity which was fine, I then checked all the neutrals and live on the pcb which was fine.

The pump is connected to the pcb, and the voltage is sent from the pcb to the pump, I am suspecting that it has to be the pcb. What do you think, any comment would be great..


Thanks

 

[swbjackson]

Have you checked for a live feed at the fan?

MIke

 

[gas1981]

yes i have live on the fan. again i have live on live and neutral, manufacturers said that ok and he suggested is the air pressure switch but is not coz i linked it out

 

[Agile]

I think this boiler has a system flow switch.

Is this being operated when the pump starts?

You have not made it totally clear but is the pump even starting?

Tony

 

[gas1981]

sorry yes the pump is starting and yes the flow switch are fine and making contact, i have tried and checked all components including thermisters and there appear ok

 

[gas4you]

Has this one the ignition pcb as well?

It could be checking the aps first and getting a bad answer, so not letting the fan run.

But then you say you have 240 VAC at the fan terminals

If this is really the case then it sounds as if the fan needs replacing. In this case the aps won't come into the equation until the fan starts.

 

[gas1981]

Has this one the ignition pcb as well?

It could be checking the aps first and getting a bad answer, so not letting the fan run.

But then you say you have 240 VAC at the fan terminals

If this is really the case then it sounds as if the fan needs replacing. In this case the aps won't come into the equation until the fan starts.

it does not have a ignition pcb, and the air pressure switch is fine, fan appears to be ok coz is not stuck

 

[gas4you]

Ok, but if the fan terminals are live with 240VAC, then to me it can only be a fan fault.

Fans do have other faults than being stuck

 

[gas1981]

i was told by the manufacturers that the fan will always be 240v on both terminals

 

[gas4you]

Only when it is supposed to be spinning.

 

[gas1981]

true, but why does the air pressure switch not make, why is the pump reverse, it has to be the pcb

 

[Agile]

The air pressure switch is not making because the fan is not running!

I have a horrible suspicion that you are not using a multimeter!

Have you measured 240vac across the fan connections and the fan is not rotating?

If so have you measured the resistance of the fan coil?

Tony

 

[diy]

if your getting 240 at the fan , and you say thats ok what are you getting at the pcb

 

[swbjackson]

It sounds to me like you are trying to over analyse the problem. Get back to basics. Stand back and look at the boiler. At what point in the ignition sequence is it failing? This will then point you in the direction of the failed component.

General ignition sequence is call for heat, fan runs, aps makes, pilot/low burner lights, flame detected, main burner lights.

In your case you are saying the fan doesn't run but pump does. To me that indicates a call for heat which narrows the fault down. Next test for power at the fan. You say you are getting 240v at the fan but it isn't running. If it really is 240v then the fan must be knackered but as Tony says are you using a multimeter or a volt stick/neon. If it's a volt stick or neon they can read induced currents so are no good for fault finding.

Mike

 

[gas1981]

It sounds to me like you are trying to over analyse the problem. Get back to basics. Stand back and look at the boiler. At what point in the ignition sequence is it failing? This will then point you in the direction of the failed component.

General ignition sequence is call for heat, fan runs, aps makes, pilot/low burner lights, flame detected, main burner lights.

In your case you are saying the fan doesn't run but pump does. To me that indicates a call for heat which narrows the fault down. Next test for power at the fan. You say you are getting 240v at the fan but it isn't running. If it really is 240v then the fan must be knackered but as Tony says are you using a multimeter or a volt stick/neon. If it's a volt stick or neon they can read induced currents so are no good for fault finding.

Mike

Thanks for the reply, the reason I have suspected the pcb was because when I tested the fan with my multimeter on live to neutral I got 0volt, however when I tested it against live to earth I got 240v and when I tested it agains neutral to earth I got 240, I suspected I have a neutral fault, however when I had a look at the manufacturers instruction is stated:

When there is no demand, there is approx 180vac to both connections on the fan and all connection on the aps.

When I called for demand for hot water, divertor valves moves and makes the flow switch, then the dhw light illuminates, then the pcb send power to pump and pump runs, then it checkes it interlock which are all ok.

Now it should check the aps in open circuit, but it does not and the fan does not work either

Yes I have 240 volts on live and neutral on the fan this is because if there no demand there will be 240v approx as per manufactur instruction