Hot Bath tap not so hot anymore

thor

I have a Vaillent central heating system that is starting to act a bit strange. everything is working fine apart from the hot water for the bath. The water no longer gets hot, it heats up but stops short of very mild. The odd thing is that the sink next to the bath can still supply almost scaldingly hot water.
So does anyone know how this could occur? Is it an obvious fault or could there be settings which can control the temperatures of the taps seperately. No one has been tampering with the system and I can't think of why the bath tap has suddenly cooled down.

weekendwarrior

This is a strange one, are you sure the tap is opening fully?

If it is not then see here- Tap repair


If it is I do not have a clue, sorry.

ormus

dont open the tap too far!
a combi can only supply so much hot water at a time. thats prob why the basin tap can supply very hot and the bath tap cannot.
(tap maybe faulty too).

ps.
my bath takes ages to fill. hence we use showers almost exclusively.

thor

The bath tap reaches it's maximum flow rate after being rotated to about 50% of the way to being fully open and has always been this way. It used to get much hotter but even when I reduce the flow the water still comes out as warm. I don't think that the tap is faulty but if it was how could this affect the temperture of the water?

Canucklehead

Hi
So if nothing has changed and no work has been done to anything in the house that would affect the water or boiler, such as new water mains into the house or work to the boiler, then the only thing left is the actual boiler itself (I assume it's a combi?)
It may not be firing up to it's full rate for hot water.

Corgi Guy.

thor

Well there is no water tank so I guess it must be a combi system. And no work has been done on it or things changed so it looks like I'm going to have to get professional help. I'm going to dig out the paperwork to see if I am still within the warranty period(fingers crossed)

Canucklehead

Hi

One other thing...
Have a look where your gas meter is. If it's in the house, has anyone accidentally knocked the control valve lever and turned it partly off?

Corgi Guy.

thor

Unlikely as all other gas appliances(cooker and gas fire) are functioning with no problems.

Ivor_Headache

Is it a mixer tap on the bath?