Hot Water Not Hot!

26 Oct 2010
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United Kingdom

I have a wierd problem with my hot water. Occasionally we find that our hot water only gets luke warm. However if we're only getting luke warm water when trying to fill the bath and we trun on the shower (or hot sink tap), the shower (or sink tap) will be ice cold but the bath tap will be red hot. If the shower is only luke warm no amount of turning on taps can get it hot, which is driving me mad in the mornings.

This doesn't appear to happen in the summer months, only in winter when the central heating is on a lot more. We had the boiler services by a Worcester accredited engineer who said the boiler was fine.

Boiler is a Worcester 28i and the shower is a Triton Capella.

Anyone got any ideas?

Cheers Simon.
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How long ago did you have it serviced?
Possibly a problem with flow rate or flow sensor.
It was about 6 months ago.

We have had the same problem before and since the service.

Is this something a decent boiler service would miss?

How can i prove this?
Did you not ask the engineer to repair this problem when you spoke to him? All sounds a bit strange to me.
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Yeah we did.

He said the boiler was fine and he suspected that the shower was back feeding, but didn't explain why he came to that conclusion.

I don't think this is right as its not just the shower that doesn't get hot.

If the bath tap is luke warm, turning on the basin tap will make the bath tap hot.

I might be wrong but the shower doesn't come into this scenario.

Is the boiler a combi, I've been assuming it is.
It is yeah. About 3 or 4 yrs old.

What i haven't done and probably need to is isolate the shower and see what happens. Been putting it off because the bath panel is tiled and the missus is a bit reluctant!
Does sound like a mixer passing cold into the hot supply.

You need someone to test at the boiler whilst the fault is happening.
If that is the case, why would it only happen at certain times.

This doesn't seem to happen in the summer, but seems to happen almost every day in the winter?
Fluctuations in water pressure from the street+cold mains water is colder in winter making the fault more obvious.
Ok, makes sense.

I'll 'get a man in' as they say!

I think i'll try to isolate the shower first as i'm guessing that should prove the theory.

Do you have single joystick taps? If so move them all to the cold position before using the shower.

I do find that Triton are the worst showers!

The basin tap is a single lever mixer, the bath taps are separate hot and cold taps.

Will try moving the basin mixer to cold. What will this do to help?

It may have been fitted without a non return valve on the supplies and leaking internally from cold to hot.


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