Vaillant ecotec plus 837 no hot water

[sootydog123]

Ok I have changed the diverter valve and still have this problem.The original had leaked a bit and was very stiff to move.

When you turn on the hot water the motor moves as it should but is very very weak.

Running through the diagnostics the screen says that the valve is in its correct position for h/w or c/h.
In the second level diag I can set the diverter vale the motor seems to energise but the valve does not move as watched with a torch.

This is leading me to believe the pcb is shot and not sending enough juice through to move the diverter valve.

Any one out there help?

 

[Agile]

That sounds very likely but when you connect the old diverter to the plug does that move?

If you want to properly diagnose the fault you would connect a scope and measure the voltage applied to the stepper motor.

With a new PCB added to the cost would it not have been cheaper to have had a fixed price repair or one of the many boiler annual cover plans?

Tony

 

[sootydog123]

Yes the old motor does move as well although very weakly.I probably will call out vaillant to do it on a fixed price repair but what do I say if the engineer says its the diverter valve no good.

 

[Agile]

Ok I have changed the diverter valve and still have this problem.The original had leaked a bit and was very stiff to move.

Any one out there help?

When we read that we expect that you fitted a new one!

So I dont see that a Vaillant engineer would have any problem.

I dont know how they respond to two faults when coming on their fixed price basis. Most only cover one part.

Tony

 

[sootydog123]

thanks for your quick response Tony, just in case I decide to bite the bullet and before shelling out on a new pcb could it be anything else.

As I said the motors for both valves operate but they are very weak in operation.

I hate these bloody new fangled boilers if coal hadn't gone up so much I will have still been on coal fired c/h.

 

[sootydog123]

After reading another post, changing the pcb would not involve combustion issues would it?

I am happy to do the plumbing side and have a lot of equipment for electrical safety checks . Not happy touching anything to do with gas side and am not qualified to do so.

 

[sootydog123]

To update changed the pcb today with the latest edition board and problem solved. The board has had 4 revisions and thanks to a helpful chap at a boiler spares store in Leeds i have the latest variant for the princely sum of £84 delivered, cost me less than the diverter valve.

So if the diverter valve just vibrates when you fit a new one and it doesn't move in and out then chances are you need a new pcb.

Now I have to find a reasonably priced boiler engineer to come and service it.

 

[oph]

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Now I have to find a reasonably priced boiler engineer to come and service it.