Ideal Classic

[newcomers]

Went on a breakdown tonight and this was the boiler.

They said it hadnt worked since friday, and was working fine before that

When I got there, the fan was stuck, so eventually managed to free it and got it going with some wd40

It then lit the pilot but when going to full gas (which it didnt), there was a banging noise coming from the gas valve.

I took the leads off of the second solonoid and got a reading of 230V, Then switched boiler off, put leads back on and it went to full gas. Switched off and tried again and the banging was back and it wouldnt go to full flame

Anyway, eventually after switching it on and off several times it went to full gas so I left it and recommended a new gas valve, is this correct? There isnt anything else that would affect the gas valve in this way is there?

Thanks

 

[ollski]

I would get the fan replaced first if it is still spinnig now I bet you it won't be in a couple of days.

 

[newcomers]

I would get the fan replaced first if it is still spinnig now I bet you it won't be in a couple of days.

Have told that to the customer, but I was more concerned about making the correct diagnosis with regard to the gas valve.

Theres no way the pcb (or any other component) would make the gas valve behave like that would there?

 

[scatmanjohn]

If you are getting 240Vac at the gas valve then the pcb is doing its job so i would say you are correct with your diagnosis.

 

[newcomers]

UPDATE:

If I leave the leads on the second solonoid, it continues to spark and the 240v to the second solonoid comes and goes quickly (on and off twice a second) and it doesnt go to full gas. You can hear the second solonoid opening and closing quickly

If I take the leads off of the second solonoid, the sparking stops once pilot is lit, and power to the leads on the second solonoid stays at 240V. The second I put the leads back on the second solonoid, it starts sparking again and the power to the second solonoid comes and goes again

Have checked polarity and continuity on ignition lead and everything is ok, does this now mean its the pcb and not the gas valve?

Thanks

 

[ollski]

What is the resistance across each solenoid....sounds like a solenoid fault to me.

 

[newcomers]

What is the resistance across each solenoid....sounds like a solenoid fault to me.

This is with the new gas valve....

 

[ollski]

Which classic is it and which gas valve?, still sounds like the main solenoid chattering.

 

[geoff@cetltd]

Went on a breakdown tonight and this was the boiler.

When I got there, the fan was stuck, so eventually managed to free it and got it going with some wd40

Assuming it's a claassic not a classic II

is the cooling fan on the end of the shaft to cool the fan motor ?

If not, you really are on borrowed time - the whole bobbin can just disintegrate

WD40 is only a bodge to buy you enough time to get a new fan. Once the grease in the bearings has gone, they have to be changed

 

[newcomers]

Its the classic FF350....


yeah that part is still on the fan, have told him it needs a new one.

Surely if it was the gas valve, the new one wouldnt be doing the same thing? And would that affect the power to the 2nd solonoid when connected? Like I said, on both valves, when the leads to the second solonoid are disconnected, the power statys at 240V, but when connected to the gas valve, it starts sparking again and power comes on and off quicky to the second solonoid

 

[geoff@cetltd]

The "classic" fault with the classic pcb (25B) is the fan relayif this is not reliably powering the fan, the whole boiler could be cycling

Power to the pilot and spark occur when the APS moves to the NO position

Once the pcb senses the pilot is alight, it opens the main gas valve

By measuring the voltages to the gas valves it has to be possible to isolate where the problem lies

 

[Rob]

it sounds like a faulty component on the PCB, and will only behave faulty when current is being drawn i.e connected to solenoid.

 

[geoff@cetltd]

Can't say without actually measuring voltages, can you ?

... wirra PROPER METER

 

[newcomers]

Changed pcb and all is now working