Vailant VCW GB 242e Boiler Not hot water

[Robbie54]

My Vaillant Boiler does not heat the water enough to have a decent bath. I did have a faulty temperature control valve (the one you adjust for summer and winter) and have replaced it, but it still does not supply water to a decent temperature. As a non plumber can I do anything about this. Is it woth repairing and can I get hold of a valliant comptent engineer in Newcastle/ Tynemouth area

Cheers

 

[Joe 2017]

most likely boiler is working fine, what the flow rate and what the temp rise

 

[Robbie54]

BOiler does seem to ignite ok Central heating working fine. Dont have means to check the flow rate or temperature. Just know I can put my hand under it without any discomfort. I can get hotter water by turning the tap down

 

[twgas]

Time water filling a bucket for flow rate, buy a thermometer, put in cold water - take reading - put in hot water take reading, hot minus cold = temp rise.

 

[hym]

Possible low burner pressure, you need an engineer as these valves do get out of calibration. There was a Vaillant excersise on valve replacement quite some years ago but only done on open flues as i remember. You need a guy who is aware how to set these valves. Or as i get alot in my district your calorifior(bit where hot water is heated) is scaled or blocked so burner pressure cutting down prematurely. More than likely the later at a guess. Either way hunt for a guy or lass who is up to speed on earlier Vaillants.

 

[hym]

From your post i was assuming all was fine but water has started to cool over a period of time with the same flow rate. As the other posts are correct on flow rates

 

[Agile]

Much more likely the boiler is working fine but just not meeting the expectations of the user.

If he cannot measure the flow rate from the hot tap he is not be able to do anything further as there is no indication the boiler is not working fine.

He could also measure the gas rate at the meter but that is more complicated than measuring the flow rate.

He seems to have no option other than to call a competent boiler engineer.

Tony

 

[hym]

Yeah as my post said,,,,assuming everthing was ok But has deteriated. But yeah Agile Competent engineer req

 

[Robbie54]

Don't really need a thermometer. With Tap turned full on the water temperature gets hand hot after running tap for a while.
Turning flow down on tap will increase the temperature but have to wait again.

I have a shower which I can use and get a reasonable shower but would like it to be hotter.
Since fitting the new temperature control vale (thermostat regulator I think) I need to turn the tap on at the sink to create sufficient flow to ignite the burner. Once ignited I turn the tap off and jump in the shower. Trying hard to hang onto it but think this could be the end of my Vaillant 242E

 

[Agile]

How can I get this across to you?

For us to know if your boiler is working OK we need to know the HW flow rate in litres per minute! We are scientists not footballers!

We cannot guess that. Its grade "C" of three GCSE !

Tony

 

[Robbie54]

Duh silly me

Not looking for a scientist, just a decent discussion about a boiler.

From hot water tap at sink it takes 70 seconds to fill a 10 litre bucket that works out at 8.5 litres a minue on my abacus

 

[Agile]

Good! Some concrete facts at last, well one at least.

24 kW power will heat about 9 li/min by about 35° !

So 8.5 li/min might be heated by about 37°.

But as the incoming water is probably at about 2-4° then its only going to be passably warm and not hot !

But thats assuming your boiler is working to 100% of its specification. Take out 10-20% for dirt/scaling and that makes the water only warm. If the gas settings are a bit low then thats lower still.

Reduce the flow rate ( turn down taps ! ) by about 10-20% and you will probably be happy with the DHW !

Tony