Unvented cylinder installation

[ImranF]

Hi All,

We want to replace vented with unvented cylinder but cannot find any decent plumber in North West London to carry out the works.

Every plumber I have called doesn't even bother to check water pressure or even flow rates. Not even British gas.

Not sure what to do now.

Currently have 2 bathrooms, one in the loft serviced via Stuart Turner pump 3bar monsoon. 1st floor bathroom serviced via the cold and hot tanks. 1st floor has obviously poor pressure and flow rates.

Mains coming in is 25mm mdpe. But unfortunately whoever installed kitchen decided to reduce it to 15mm before the stopcock.

I installed garden tap. With water pressure guage currently measuring between 3.2 and 4.2 bar static pressure. When opening 1 tap it reduces right down to 2.4bar and when also cold water tank is refilling as well it stays around 2.2bar. I believe if pipework under kitchen sink gets reworked i.e 22mm instead of 15mm that would improve the dynamic pressure. Also water flow rates are around 32 litres a minute.

I believe unvented cylinder is suitable but ideally I would prefer finding a decent plumber who would also check this before installing unvented cylinder. I don't understand why any decent plumber would not carry out basic tests before agreeing to install unvented cylinder. One plumber also mentioned not to follow the advice on any forums when I specified that dynamic pressure is more important than static pressure.

Only other option would be to have both bathrooms serviced by the shower pump.

Can anyone recommend decent plumber in North West London. If not how else could I guarantee that the pressure and flow rates are suitable for unvented cylinder.

Anyone feedback would be really helpful.

 

[Ben-gee]

To be fair that is extremely good flow rate and pressure, with a quick visual check and local knowledge of your street a good local plumber may well forgo an actual test. However I would’ve expected them to comment on this if you were present when they were surveying the potential job.

 

[gpbeck]

Is the problem just the upstairs bathroom? Are the taps/shower control there specified for lower pressures from a tank, or the usual high pressure ones? This could explain the low flows.

 

[Basher]

We had a recent update from old vented Fortic tank to unvented. Our pressure is over 5 bar, but we get nowhere near your amazing 32L/min since much of our pipework is in 15mm, more like 22L/min
The update works really well. Two bathrooms and one en-suite over 3 floors. Brilliant rain shower is not affected by turning on taps elsewhere etc.

I really feel you shouldn't be put off plumbers because they won't measure your flow/pressure (especially as you know what those figures are!). They probably have a good feel for the parameters in your area, as has been said.

I completely sympathise with wanting to pick the right plumber for the job, and a G3 qualified one at that, but you really need personal recommendations from independent local people or friends. Not from internet star ratings , which clearly you aren't.

 

[Timmy D]

Imran, I can’t pm you. Drop me a pm, I should be able to point you in the right direction.

 

[ImranF]

We had a recent update from old vented Fortic tank to unvented. Our pressure is over 5 bar, but we get nowhere near your amazing 32L/min since much of our pipework is in 15mm, more like 22L/min
The update works really well. Two bathrooms and one en-suite over 3 floors. Brilliant rain shower is not affected by turning on taps elsewhere etc.

I really feel you shouldn't be put off plumbers because they won't measure your flow/pressure (especially as you know what those figures are!). They probably have a good feel for the parameters in your area, as has been said.

I completely sympathise with wanting to pick the right plumber for the job, and a G3 qualified one at that, but you really need personal recommendations from independent local people or friends. Not from internet star ratings , which clearly you aren't.

Measured today again. Now only 22lpm. It fluctuates a lot. Problem is to do best test I would need to stop the supply to the tank in the loft or wait till I am 100% certain no one has used the cold water.

Also Wickes installed kitchen years ago. Plumber for some reason reduced 25mm mdpe to 15mm before stopcock. I would have thought they would have simply used 25 to 22 stopcock. Would this cause also the dynamic pressure to drop as seem to loose 1 bar pressure when the first tap is turned open.