Odd HW problem

dreaddan

HI I've got a very odd problem with the HW in the house.
We've been in the house for nearly a year now, it looks like the previous owners have done most if not all the work to the house. Not all of it was done with all due care as it should have been done with

Anyways, we have a combi up stairs and the main bathroom down stairs at the end of a extension.
If we have the boiler @ 50% for HW the water round the house gets pritty hot but not too hot.

Except in the bath, where it's barely luke warm, if we set the boiler to 100% it will get warm after a while but it takes ages before the HW comes out..

does any one know why this may happen?

Dan
p.s. sorry for my spelling

cport80

We have a similar problem caused by old taps. The problem is when you turn the hot tap on full the throughput is too much so the water comes out slightly cooler. We get around it by running the bath slower for now.

If your boiler hasn't been serviced then I'd get a corgi plumber out to have a look just to be safe.

plasticfantastic

dan - do you have a mixer tap on your bath? I've seen this problem before - esp when the pressure of the cold water is significantly greater than the hot. If this is this case, might want to consider changing for thermostatic mixer.

pf

dreaddan

cport80: I've not tryed that. I'll give it a go later and see what happends.

plasticfantastic: it is a mixer but also happens with no cold flowing at all.

dreaddan

cport80: done a little test.
I have to run the bath @ 1/4 of a turn before it starts to cool down.
By 2 turns it's luke walm.
Will run it slower now.

Thanks
Dan

plumb1_2

The problem when combi,s are install to existing systems,is that the hot water supply pipes are 22mm,and the HW outlet from combi,s is only 15mm,so you get a lot of cool standing water sitting in the pipes and the water from the combi has to mix with this,so you will have to draw this water off before you get hot water,and often airiated(milky)

dreaddan

Well that would explain it.
Had the first hot bath last night since moving in to the house Well pleased.

Dan

plumb1_2

And less smelly ;D ;D ;D

dreaddan

Luckerly we have a on suite shower upstairs

cport80

Thanks for the explanation plumb1.

That airiated flow sounds familiar. At the time we had our boiler replaced we were just glad to have the heating going again after 6 weeks without it (last nov & dec).