Hot water pressure problem

[jmcclintock77]

hi,

looking for some advice: - a gravity fed low pressure system and there is only a trickle of hot water coming out of the bath tap. (bath/shower mixer)
All the other hot taps in the house (including the bathroom basin) have adequate pressure through the hot tap. The mixer tap is suitable for low pressure systems. I replaced the mixer tap which hasnt solved the problem. I took the taps off all together and turned the water back on and hardly got any flow from the hot so know its not the tap. I'm not sure what it could be due to the bathroom basin being so close to the bath (and higher than the bath) but thats still fine.

At the moment I've not been under the bath as its tiled in so they'd have to be removed.

Could I need some sort of pump fitting ???

Any suggestions would be much appreciated.

Cheers, James

 

[galaxy_plumbing]

has this problem always been there or just recently happened? could be a blockage as other taps working, though

 

[glenno1]

Air lock mebee,open the hot,then put hand over the spout to stop water coming out,then slowly open the cold.Let me know if this works

 

[Phil]

You've changed the taps without talking the bath panel off? You'll have to show me how to do that. :earmuffs:

Probably a unioned mixertap though?

I'd start off with my wetvac on the hot feed and see if I can pull an airlock/loft insulation through.

 

[stevetheplumber]

if it just the tap youve fitted and everything else is back as it was before then its the tap in some way,try turning the water of remove the tap body and get some one else to turn on and see what the flow is like then

when you first turn on the tap is there a full flow which then slows ?or is it slow from start?

are the supplies balanced ie both fed from same tank?if you have mains cold it could push the hot back
if all that fails put the old mixer back see if thats slow now

 

[Mike Jackson]

There could be an isolating valve under the bath which is partially shut or a flexi (sorry system) which is twisted.

I'd say you need to look under the bath to confirm the pipework. I hate people that don't allow access under baths.

 

[jmcclintock77]

Thanks for the advice.

I've tried the air lock scenario - no joy. The mixer tap has the crome elbows sat on the bath which the tap fits onto which is how i took it off without going under the bath. When the pipes are open there is no flow from the hot straight from the beginning. It just trickles out. The hot flies out which makes me think the cold is fed from the mains.

This hot pressure in that tap has always been bad.

Think i'm going to have to bite the bullet and start removing tiles.

Can we rule out the need for a pump if its only the bath tap?

 

[Mike Jackson]

Yes. The flow from a bath tap will always look worse than from a basin tap due to the larger orifice but not that much worse.