Bath hot water not hot - Piglet John or anyone else who can help!

[petshopgirls]

I have got a combi boiler serving an ensuite bathroom and heating etc. the shower (separate to the bath) is hot and the sink water is hot but the bath hot water tap is intermittent and it's impossible to run a hot bath. It ends up lukewarm.

This bathroom was installed around a year ago and the bath was fine until about two months ago. Any ideas?

Make and model of boiler?

Run the hot bath tap into a bucket, time it to full, calculate how many litres per minute it delivers. Do the same at the kitchen hot tap. Are they equally hot?

Do this after you have had the central heating turned off for an hour at the timer or wall thermostat. Without turning the heating back on, but with the hot bath tap running, feel the tops of all the radiators. Have the ones nearest the boiler warmed up?

We will do that Piglet - thanks.
I do know that the bath tap is the only one with a hotness issue.
Will report back on the litres per minute thing. Thanks for your help with this.

Salty - I think it's an Alpha Ocean boiler. Oldish and a bit obscure according to my plumber.

Diverter valve are suspect on these. Piglet John was hinting along the same line. If the rads get hot while hot water is running then that would be the issue.

I will check.

Would that explain the way it was okay until two months ago? Would the valve have just gone?

Ooh we have this problem as well! Our boiler is 5? Yrs old and serviced/checked every year. It has bern the last few months that it does this snd its bloody annoying!

There are various causes for this problem with some more likely on certain boilers than others. What is the 5 year old boiler?

Errm.i will have to.go and have a look, will report back later, slightly mad here today trying to tidy up for visitors tomorrow.

It's an Alpha Ocean 280p to be more specific.

Sorry for namechange confusion!

Have you tried not turning hot tap on full flow? That worked for us - boiler doesn't have to work as hard to heat so much water

yes, that is one of the common causes of lukewarm water from a combi in winter.

We will know when we hear the litres-per-minute measurement, and the warm-radiators result.

Yes I have tried the hot tap on less full flow and sadly it didn't work. Sorry not done the litres test yet as had family over all day it I will! Need to find a bucket too and check its capacity...