Low pressure/slow hot water supply

[MikeJM]

Advice please.
The hot water supply to my kitchen sink tap has very low pressure and it takes a while for the hot water to come through.
We live in a bungalow with the hot water cylinder in the centre of the building (oil fired/gravity fed system), but the hot water pipework to the kitchen runs under the concrete floor to the far end of the building to serve the bathroom (where the water supply is ok) before returning to the kitchen tap.
I guess the long route is the reason for the low pressure/temp problem?
Would it be feasable if I tee`d off the HW supply from the cylinder outlet and ran a 22mm pipe up and across the loft and direct down to the kitchen where I could reduce it to 15mm for the sink. This would halve the distance for the HW to travel and hopefully improve the supply.
If any pro`s think this is feasable I would be grateful for any advice, ie: is there a min/max height for the new pipe to run up vertical from the cylinder before running horizontal across the loft?
Any advice welcomed.
Thanks
Mike

 

[gas4you]

Unfortunately in a bungalow ther is not much height for the cold tank to be sited to obtain a good pressure.

Has it always been like this? If not check all gate valves are open fully. Also try putting a hose on the cold mains tap to the hot tap and back feeding it to see if there is a blockage or air lock.

What you are envisaging to do is possible but unless you increase the height of the storage tank in the loft it probably wont help.

 

[MikeJM]

Hi Dave
Thanks for reply.
We moved into the bungalow in Jan this year and the problem has been there since then, almost certainly alwaye there. The system is quite basic and some 20 years old i think, although the boiler is only 3-4 years old. The water takes a long time to heat up when starting the boiler up from cold anyway, possibly because as you say there is not a lot of headroom between the loft tank and the hw cylinder (aprox 1300mm from top of cylinder to bottom of tank).
I`ve drained the system a couple of times to flush through the discoloured water we had before the water board fitted a filter in the main supply to our bungalow (this is common in our area as an old iron mains pipe is still in use by the water board) so I dont think there is a blockage anywhere or air locks.
For whats involved I think I will give it a try and hope it works.
Thanks for the advice.
Mike

 

[rob1976]

hi mike

are the taps new? it could be that the cold water is pushing back int the hot pipework due to the pressure difference, therefore affecting the flow and temperature, a non return valve fitted to the hot should remedy this, its a cheap solution and worth ago perhaps?

rather than repiping everything have you considered installing a h/w pump?

cheers


rob

 

[MikeJM]

Hi Rob
Thanks for the info.
At the moment i`m in the process of fitting a new kitchen and would have liked to get this sorted out along the way. The old mixer tap was some 30 years old so the problem may have been the tap any way but the cold pressure was good from the same tap.
What i would welcome are any comments on my idea to run a 22mm new supply as mentioned earlier, any height implications etc for pipework??
Thanks anyway
Mike

 

[petetheleak]

Mike I Would not recomend running pipe as you describe M8 ,leaving yourself prone to air locks. Your always going to get good cold water flow and pressure at sink as this is mains fed.
Hard to comment on other system without looking But if you really want to improve the flow/ pressure fit a indirect pressure hot water tank which will solve problem .