Bath water luke warm

[xfr]

i have a Baxi duotec combi boiler in the garage.
My problem is the water coming out of the hot tap in the bath is barely luke warm.Any idea what's causing this..

 

[oilhead]

You are trying to get more hot water than the boiler is designed to produce. Turn the hot tap down. It takes longer to run the bath but it will be hot.

 

[xfr]

it has not been a problem until now.
Water used to be hot,so there must be a problem some where.

 

[Gas2Air]

it has not been a problem until now.
Water used to be hot,so there must be a problem some where.

Flow rate, pressure and temperature rise from boiler. Have you checked them? I doubt it. What tap is it? Are all other hot taps ok?

 

[oilhead]

If you have had this boiler to replace the Glowworm you used to have, then it must still be under warranty. Have you contacted the installer?

 

[WilkyWay]

You might notice a difference in the winter due to the temperature of the water coming into the property.
The boiler will give a temperature rise of say 30 degrees at 12lpm for example. So in the summer when water is at 15 degrees-ish you will have (15+30) 45 degree water, in the winter the water coming in could be down to 2-3 degrees giving (2+30) 32 degrees at the tap. Big difference when you're having a bath or shower. You can compensate for this by reducing the flow rate at the tap, if it gets hotter when you slow it down then I would put it down to that.

 

[xfr]

If you have had this boiler to replace the Glowworm you used to have, then it must still be under warranty. Have you contacted the installer?

its actually my sisters boiler.its been in about 3 year's
As it happens I did change to the same boiler in November, with a 10 year warranty.

 

[oilhead]

What size are the bath taps and what size is the pipework to the hot tap? I'll wager that the supply is a 22mm pipe left from the days of indirect DHW storage. This combination allows far too much water to be drawn through the boiler. See above for explanation of the capacity and the effect of winter water supply temperature. Can you answer the question about the other hot taps?