Vaillant Turbomax 242/282 not igniting.

[PJBonoVox]

Hi all

Wonder if anyone could help? Just today we've started to have a problem with the above boiler. When we turn the central heating on, run the hot tap or even turn the dial to manually ignite the boiler, it's not firing up.

Before I start--The hot water request switch seems to be working fine, the central heating switch is fine, the fan is firing up ok and the water pressure appears to be good.

All the lights & noises up until the point of ignition are 100% normal except I'm not hearing the 'ticking' sound of the electrode. Once it fails to light (presumably because the electrode isn't operating) the 'ignition lockout' light comes on and I'm back to square one. I'm guessing something to do with the ignition electrodes or something similar is at fault but not sure where to start troubleshooting.

Where's a good place to start? Don't mind getting my hands dirty with this.

Any advice would be most appreciated

(PS, it's had this issue before but resolved itself within a couple of hours)

 

[Gasguru]

Assuming it's got the black control panel and green knobs then a starting point would be to check the differential pressure switch is operating.

Lower the controls panel (single screw). Look to see if the white plastic bit lifts up to release the microswitch on the diff pressure switch assembly (left and above the pump.

 

[PJBonoVox]

Hi man, thanks for the reply. Yes, the boiler I have is as you describe

I've used the manual to locate that switch, but what should trigger the white arm to release the switch? If I try and start the ignition sequence should it move then?

I've put a little mirror in to watch the microswitch and the arm whilst turning the bottom green dial (to force the ignition) and it doesn't move at all, not even a tiny bit.

Where should I go from here?

Thanks for your help so far

 

[mickyg]

It detects pump pressure. When/If the pump starts the arm on the switch should move. So: check pump yes/no > check switch arm moving off switch >yes/no

If its the switch then often it blocks up in the connecting tubes.

 

[PJBonoVox]

Thanks for the info, I'll take a look.

Quick question though-- The boiler doesn't ignite when using either the central heating or the hot water. If that switch operates based on whether the pump is working, doesn't that mean that the hot water should still work?

Or would the hot water system also use the pump?

Thanks

 

[ChrisR]

would the hot water system also use the pump?

yES, IT CIRCULATES BOILER WATER BETEEN THE HEAT EXCHANGERS.
oops sorry

 

[PJBonoVox]

Ok, so I've checked it out. That switch isn't moving at all.

The pump is getting extremely hot after just 4 or 5 attempts and igniting the boiler (only a few seconds each time) and certainly doesn't sound like it's doing anything.

Is it possible the pump has died? Is there any way to test it?

 

[Gasguru]

You may find the pump impeller is jammed or the starting torque is too low. Unscrew the plug on the front and see if the shaft will easily turn...be prepared for water to dribble out.

 

[PJBonoVox]

Just to let anyone know who is in the same situation-- It WAS the pump at fault.

We removed it, freed it up a bit and plugged into 240v and it started working again so all was well.

If it goes again I'll replace it, but the problem was definitely identified and solved. Thanks for all the help!

 

[garyatkinson]

I have the same symptoms and have checked the pump suggestion and it moves freely.

Sorry to hijack the thread, but with similar symptoms and the same boiler (Turbomax VUW 282e) I hope thats all OK with you guys?

Like PJBonoVox, the boiler doesn't ignite and there aren't the usual ht clicks before ignition. If I reset the 'ignition lockout', with the water still running, it will fire up (not always at the first attempt, sometimes 2nd or 3rd).

If after it has ignited, I leave it off for a few minutes, it will ignite fine . If I leave it for any longer, I have to repeat the ignitition lockout reset, etc.

Any help gratefully received.

 

[garyatkinson]

It detects pump pressure. When/If the pump starts the arm on the switch should move. So: check pump yes/no > check switch arm moving off switch >yes/no

If its the switch then often it blocks up in the connecting tubes.

Shorted the terminals on the switch and it ignites!!! when you say it blocks up in the tubes, do you mean the internal tubes of the switch or the copper tube from the diverter?

I ask because I don't want to replace only the switch if it the copper tube is also likely to be blocked.

I've ordered a new divertor valve (as mine has been dripping for a year or so ) and will replace with the switch at the same time.

 

[mickyg]

it blocks in the tubes and where it connects into the hydraulics above the pump and on the DV.

 

[FreddieL]

Assuming it's got the black control panel and green knobs then a starting point would be to check the differential pressure switch is operating.

Lower the controls panel (single screw). Look to see if the white plastic bit lifts up to release the microswitch on the diff pressure switch assembly (left and above the pump.

I'm a newbie on this and have not a clue what to do.

Is there a video I might watch?

Just back to flat, boiler is v rarely used but today the burner lock out indicator clicks in whenever I turn hot water tap.

V sad.

Thank you.

 

[Agile]

Are you sure you have a gas supply?

Working cooker or hob?

Tony