Vaillant Ecotec 937 Plus, no hot water

[YRen]

I went on holiday for a ~9 weeks and turned the boiler off. Now I returned, turned it back on, but no hot water. Been doing this for the past few years, and everything was fine. There are no error codes. Every time I turn on the hot water tap, I hear the boiler also turning on, and the temperature rising to ~80 degrees the display. However I don't receive any hot water. What could be the problem?

 

[hertsboilers]

Which version is it? With two big dial knobs or just push buttons?

This is a boiler even most of gas engineers are struggling with to repair. If you have already completed some basic checks, like water pressure etc, then I suggest you call Vaillant for a fixed price repair.

 

[hertsboilers]

Most of common failed parts on this boiler is the shunt pump, but if it fails, you normally get some error code.

 

[YRen]

The one with dials. I think the analog pressure gauge is broken, it's stuck at zero while the display shoes something else (but that shouldn't effect anything). Apart from that everything else looks fine.

 

[hertsboilers]

The one with dials. I think the analog pressure gauge is broken, it's stuck at zero while the display shoes something else (but that shouldn't effect anything). Apart from that everything else looks fine.

It is likely opposite. Digital sensor is blocked to give a wrong reading and analogue gauge is correct.

 

[YRen]

Well I have another Vaillant boiler for another floor and the analog gauge is stuck shows zero too, and that boiler works fine.

 

[hertsboilers]

Well I have another Vaillant boiler for another floor and the analog gauge is stuck shows zero too, and that boiler works fine.

Thanks for teaching me that!

 

[Hason]

If you press bottom left and top right buttons it will give a fault code in past, if gauge is on zero but you press the bottom left button it will say pressure. Lkely to be pressure sensor blocked,vessel flat,prv may need replacing. On the hot water side, either flow sensor not operating,hw pump,pcb on top of boiler,dip pipe can also fold internally so could be an issue, has f81 came up? Is access under boilet ok ie can lay under boiler??.
Get a fixed price repair via vaillant,will take a couple of hours to sort. Nothing major i would expect

 

[Agile]

You don't seem to be very interested in getting your boilers serviced and gauge faults corrected do you?