Shower pressure issue

[Vic8710]

Looking for some help with the shower pressure issue.

Issue had started after my boiler was replaced to a combi-boiler (worcester bosch greenstar 30i) about a year ago now. Hot water the shower is supplied from the combi boiler downstairs with cold water coming from the cold water tank in the loft.

The shower mixer that i had at the time (Mira pace) had started making a fairly loud noise and losing pressure every so often. Recently I decided to replace the shower mixer with (Bristan Sonqiue2 Bristan Sonqiue2 Thermostatic Shower Valve With Riser Kit Chrome - https://www.qssupplies.co.uk/bathroom-furniture-shower-taps/82475.htm) this had resulted in no weird noise being made by the shower but the water pressure being even worse. Initially pressure seems fine but about 30 seconds in it drops and then fluctuates.

Thanks in advance for your help with this as its driving me crazy.

 

[exedon2]

Are you absolutely certain the cold feed for the shower is tank feed? If it is unequal pressure's probably the problem If the tank is feeding shower cold is it feeding any thing else?

 

[Vic8710]

Are you absolutely certain the cold feed for the shower is tank feed? If it is unequal pressure's probably the problem If the tank is feeding shower cold is it feeding any thing else?

There's a valve in the loft that comes out of the water tank and if shut off there is no cold water being fed to the shower or any of the taps. The tank is not feeding anything else as I have all other taps off as I test it.

 

[exedon2]

Its difficult to see why the tank was not disconnected and the cold feed from the tank connected to the mains supply when your boiler was changed.
That would give you balanced supplies to your shower.
There may be some odd specific reason this was not done maybe go back to your boiler installer and ask the question?

 

[Vic8710]

Its difficult to see why the tank was not disconnected and the cold feed from the tank connected to the mains supply when your boiler was changed.
That would give you balanced supplies to your shower.
There may be some odd specific reason this was not done maybe go back to your boiler installer and ask the question?

thanks will lift up any documentation that i have for the work see if that was included. In my case would fitting one of these resolve the issue Water Pressure Equalising Valve ? Water Pressure Equalising Valve - https://www.bes.co.uk/water-pressure-equalising-valve-16711/

 

[John.g]

That will only give you water at the lower pressure so no good IMO. Can/have you set the HW (tap symbol?) temperature on the boiler to 40/45C, no mixing required then and may work until you get mains cold to the shower.

 

[exedon2]

As John has said above the easily and simple answer is to connect shower cold to mains.

 

[Vic8710]

thanks i appreciate your answers will reach out to the company that did the the boiler installation.

If i was to undertake the work myself how involved would it be to redirect the water to bypass the water tank?

 

[exedon2]

Could be as easy as cut mains cold to tank cut shower feed push fit elbow on each one link with length of tube.

 

[Vic8710]

Had a reply below back from the one of the big energy firms that had done the boiler replacement for me. I feel that they are being unreasonable with me and could have at least mentioned that I will need to get cold water reconfigured to avoid issues with shower pressure.

As part of the boiler installation, the scope wouldn’t include the re-configuration of the cold water supplies to any exiting cold outlet in the property. You will now get cold main supply pressure through the hot tap (with you having a combi boiler installed) but existing tap outlets or in this case a gravity fed shower from the cold water storage tank, would not be re-configured.

 

[Ric2013]

If they didn't mention it, I agree. Especially as, with presumably no check valves on a shower mixer on unbalanced pressures they have left an illegal installation in breach of the Water Regulations which would have been previously compliant as the previous pressures were balanced. Any workman has a responsibility to carry out work to a reasonable standard: this fails in this respect.

Being practical, if the shower used to work on gravity okay, then a pressure reducing valve or pressure equalising valve to the shower hot inlet should make the shower work how it used to before the combi was fitted. It'll be lower pressure than now, but that's how it was before.

 

[Vic8710]

Got upto the loft to have a quick look and as expected found the cold water tank full and still in full use. Took some pictures below. I can see a 15mm pipe going from the airing cupboard to the loft and connected into the water talk as a feed. I have also traced a 22m pipe from the water tank coming down to the airing cupboard. Am i right in thinking that all I need to do it to join the two pipes in the airing cupboard together after I had drained the water tank? That would also mean that the toilet and the downstairs toilet would be supplied by the mains water pressure instead of the water tank, can there be any issues with that?

As always thanks for your help.

 

[Ric2013]

You're suggesting connecting the feed to the cold water storage cistern to the outlet from the same cistern? May not be the best or neatest way to do it, but I can't really see that not working and you'll have a nice water butt someone will be happy to have. Just bear in mind if there's any bad plumbing on that cold, then you are increasing the pressure significantly, so be vigilant.

Could that capped pipe above your towels be the redundant feed to the old cylinder? To have left a dead leg like that is also illegal, not to mention dead lazy - they could easily have capped it close to the loft cistern.

 

[Vic8710]

You're suggesting connecting the feed to the cold water storage cistern to the outlet from the same cistern? May not be the best or neatest way to do it, but I can't really see that not working and you'll have a nice water butt someone will be happy to have. Just bear in mind if there's any bad plumbing on that cold, then you are increasing the pressure significantly, so be vigilant.

Could that capped pipe above your towels be the redundant feed to the old cylinder? To have left a dead leg like that is also illegal, not to mention dead lazy - they could easily have capped it close to the loft cistern.

What would you suggest I do it this case as a neater solution?

Yeah the piping that I was left with is a right mess.

 

[Ric2013]

Assuming the other cistern in the loft is also redundant, the neater way would be to cut out the redundant pipework in the loft altogether (without leaving a dead-leg) and connect the gravity pipework to the mains supply downstairs, assuming you have a minimum of 15mm diameter pipe on the existing gravity cold. It would mean your isolator would be in an accessible position and you might then find you'd be able to get rid of the pipes in the loft, but it won't make you more intelligent, more attractive, or stop you gaining weight (or was that an old tobacco advert?). Depends how close your gravity cold pipework comes to your mains pipework and how easy it is to cut out the deadlegs. It may not be a reasonably practicable solution at this point in time.

 

[Vic8710]

Assuming the other cistern in the loft is also redundant, the neater way would be to cut out the redundant pipework in the loft altogether (without leaving a dead-leg) and connect the gravity pipework to the mains supply downstairs, assuming you have a minimum of 15mm diameter pipe on the existing gravity cold. It would mean your isolator would be in an accessible position and you might then find you'd be able to get rid of the pipes in the loft, but it won't make you more intelligent, more attractive, or stop you gaining weight (or was that an old tobacco advert?). Depends how close your gravity cold pipework comes to your mains pipework and how easy it is to cut out the deadlegs. It may not be a reasonably practicable solution at this point in time.

My plan was to join the two pipes together in the airing cupboard(to the left) just like what was done with the hot water pipes in the right of the picture below. Once hat is done i could get rid of all the piping and the tanks from the loft.

 

[Ric2013]

Yes. If there are no branches, then that makes sense.