Bath tap not very hot.

[ZedTheRed]

Hi All,

I'm hoping someone can help me.

I get piping hot water in the kitchen and bathroom basins. However in the bath I only get warm water and don't even have to use the cold. I have always had this problem since I moved in 6 years ago but had an electric shower so wasn't a problem.

I have now had a thermostatic mixer shower installed and if I have it at the hottest setting it is fine but I know in the winter months It would need it to be hotter.

Every plumber I have asked say I need a new better boiler as mine is too old and hasn't got enough capacity. The bolier I have is a Biasi Prisma 24SE. The reason I'm not convinced is that it works perfectly well apart from the bath so how could it be the boiler. I live in a 3 bedroom house with a kitchen and one bathroom. One plumber also said that I have 15mm pipes going into the bath instead of 22mm and that could be a problem also.

Any advice would be most appreciated.

Thanks

 

[NickH]

Is it a combi boiler ?
If so then the hot water temp will depend on the flow rate through the boiler, the flow rate of the bath taps may be higher than the other taps hence lower water temp.

 

[ZedTheRed]

Yes it is a combi boiler.

Actually the flow rate is nowhere as high as the other 2 taps.

 

[NickH]

Can you see what the pipework arrangements are,does the same pipe feed the bath and the basin hot taps ?

 

[ZedTheRed]

I can't tell as there are floor tiles layed down. The basin and the bath are opposite sides of the bathroom so I would have thought they were different pipes?

 

[justlead1]

Hi, The flow rate will always look less through a bath tap as apposed to basin tap. I would measure it via a saucepan / seconds, on both, before ripping any thing up. Good luck

 

[NickH]

Try turning the bath tap down to reduce the flow and see if it gets hotter.

 

[ZedTheRed]

Unfortunately reducing the flow makes no real difference at all.

 

[Pataing]

when running hot tap in bath also run hot tap in basin, see if this raises temp in bath tap.

 

[ZedTheRed]

Thanks for your input guys.

I turned the flow right down and yes the temperature did rise a little but not enough that I had to move my hand out of the way and to fill a bath it would probably take the whole day.

I also tried turning the hot water on in the basin and again it didn't make the bath tap much hotter.

Someone else also suggested that the hot water pipe/tap could be letting in cold water. I closed the cold water supply to the bolier and turned on the hot water tap. After the water drained out it stopped which I assume means that cold water is not going into the hot water.

Just thought I'd give you some more info.