Unvented indirect with low pressure mains

[nicolewells]

Hi,

I live in a 9yr old 3 story townhouse with showers on the 1st and 2nd floor, a bath on the 1st and toilets and basins on all three floors.
I've never been very happy with my shower and tap water pressures but have only recently investigated the issue.

The house has an unvented indirect solar cylinder on the 1st floor with the gas boiler on the 2nd floor and solar panels on the roof, although I am
waiting for a warranty replacement of the cylinder from BAXI due to an internal cylinder solar coil leak and so currently the solar loop is turned off.

The mains in pipework looks to have a 3 bar restrictor on the ground floor and then a cold water combination valve with a pre-set inlet pressure of 3.5 bar and expansion vessel pre-set pressure of 6 bar. Following this, there is an expansion vessel and pipes to the cold taps and cylinder and also a capped pipe to top-up the radiator loop.

As a test, I connected a pressure gauge to the radiator top-up pipe and got a pressure reading of 1.5 bar.

Now to my question(s)...

I believe that this is the bare minimum for a mains water feed into an unvented cylinder and can I get a booster pump (e.g. Stuart Turner Mainsboost Flomate MBF 12 - 46574) installed prior to the pre-set 3.5 bar combination value to fix?

Space is tight in the cylinder cupboard (see image) so I doubt I'd have room for a booster cylinder even though the replacement cylinder I'm expecting will have a built-in expansion tank and so I should be able to get rid of one of the existing expansion tanks...

Any responses are gratefully accepted.

 

[ShaunCorbs]

What do you get on your mains outside tap / washing machine point ?

 

[nicolewells]

Hi,

Sorry for the late reply, I have been away.

I have both. I'm unable to get to the washing machine point but have checked the pressure on the outside tap, which strangely is coming out at 3bar.

I had intended to try replacing the 3 bar filtered restrictor in the kitchen cupboard on the ground floor as I had figured that maybe this had got clogged over the last 9 years, however, the fact I'm getting the full 3 bar at the outside tap, which comes from the mains water pipe in the 1st-floor cylinder cupboard on the other side of the ground floor restrictor, shows this is not the issue.

This just leaves the higher up cold-water isolator tap and then the cold water combination valve which, following that, gives me only 1.5 bar.
So I'm now guessing that it's the combination valve that's got gunked and the isolator tap is wide open.

I'll have to see whether this is covered on my heating plan but have a feeling that I have the bare minimum coverage.