Valiant Vcw 242e

[PCRR]

Hello all,

I have an old valiant 242e where hot water flow used to be slow but water did get hot. Recently hot water flow has increased but temp decreased. Temperature adjuster valve had snapped last year so have just replaced so I can slow flow in winter like boiler advises. Now hot water is hotter but not enough. Any ideas on anything else I could look at? Water valve / microswitch do operate when I turn on hot tap.

 

[kidgreen61]

Depending on the kw rating of your boiler, it may be down to the fact that the incoming mains water is cold at this time of year, and your boiler may have more water passing through it than it is capable of heating.

It is also likely that the plate heat exchanger may be dirty on the primary side, or scaled up with limescale on the DHW side, and needs cleaning or replacing.
You probably need someone to carry out some tests to determine the exact source of the problem

 

[PCRR]

Hello, thanks for reply. Had boiler since living in house so 16 years. Water always been hotter than now so not sure it’s just due to time of year. I have just fitted a new temperature valve and set fully anti clockwise. Is the plate heat exchanger the one on the left when looking at boiler from the front. If yes can I just undo nuts on pipes. Remove and flush.

 

[kidgreen61]

That's the one.
If you undo the nuts you and the boiler electrics will get very wet, and it will end in tears.
You need the appropriate chemicals to clean it, depending what it is clogged with.

 

[PCRR]

Hello.

Do I need to isolate house mains water stop cock. Run tap to empty boiler then remove?

Can you recommend what to buy and how to clean. Water currently gets quite warm but not hot enough for bath.