Vaillant Combi Boiler VCWGB 282 EH - DHW problem

[BloggLam05]

I am only getting luke warm water on the DHW on demand. it will get hot (NOT very HOT) if i reduce the flow of water when i close the tap slightly. the central heating is working fine. i've check the pressure which is fine too. i've checked the heat exchanger for DHW and it is clear of calcium deposits.

any help will be appreciated.

Blogg

 

[BloggLam05]

I forgot to mention that the boiler is 9 yrs old.

Blogg

 

[Dan Robinson]

When the system is stone cold, does the CH flow pipe heat up when you run the hot water for a while ?

If so you diverter is goosed.


Could be a split diaphragm.

 

[BloggLam05]

Thanks Dan for your reply and will check your suggestions this w/e and let you know what's what.

thanks
bl

 

[Agile]

Why wait until the weekend?

The sooner the problem is identified the sooner it can be resolved!

Tony

 

[BloggLam05]

Dan

the CH was not hot, so i guess it's not the diverter.

anymore suggestions.

thanks
bl

 

[Gasguru]

Open all the hot taps and calculate the gas consumption.

Read the FAQ's and post back the answer.

If it all looks a little complicated, post the time in seconds for one needle revolution on an imperial meter or the index readings after 2 minutes have elapsed on a metric meter.

 

[BloggLam05]

I'd got 40 seconds for one complete revolution.

I've got no idea what it means.

any more suggestions for the DHW problem.

thanks All

BL

 

[Gasguru]

It's burning about 20% less gas than it should do, however it should still perform as good as a lower spec combi.

There are many reasons for this...from a boiler fault to the meter control valve being partially closed.

Working correctly the boiler should be able to fill a standard bucket size (to the brim) at bath temperature in 1 minute and a little less in it's current state.