DIY Doctor UK DIY Forums

First post, been advised to ask on here by friends.

We live in a maisonette. Kitchen and living room on first floor, bedrooms and bathroom on 2nd floor.

We have a Vokera combi boiler which was put in in 1998 when we moved in. This has been fine, it gets serviced every year and has had the heat exchanger replaced about 5 years ago (hard water area).

We had the bathroom done in 2007 using parts from bathstore. Installation was done by a bathroom fitter (basically a joiner/builder we know who is good at bathrooms).
All has been fine really but never been 100% happy with the thermostatic shower. It's never seemed to have much temperature range but other than that fine.

Had the boiler serviced last year (by a heating engineer, gas safe registered etc) and straight away it was like there was no heat adjustment at all on the shower. You could have a good shower but then the water temp was too cold to run a bath. Turn up the heat on the boiler to make the bath better and the shower was too hot (literally scalding). Spoke to the heating engineer, said he doesn't do showers, speak to a pumber.

Got a plumber in before christms, gas safe registered. He had a look and said the bathroom taps and shower were plumbed in wrong (hot going into cold side and vice versa). Also mentioned poor flow rates in upper taps (previous to this place I lived in London with RUBBISH water pressure). Basically on the bath taps the cold runs about three times as much as the hot (not measured it properly). He suggested replacing the boiler (on the basis of poor flow) then looking into the shower problem. He said he would come back but not heard from him, not chased him as haven't got money to replace boiler unless it needs doing. He mentioned that cold water feed might need sorting (possiblity of one feed from street feeding 2 or 3 flats).

Still got the same water temp problem.
I'm not 100% convinced boiler is to blame, if it's on it's way out then how can it run 8 radiators and heat tap water as hot as you want?

So I am stuck.
Do I replace the boiler in the hope it solves the problem? Or get the shower sorted and then look at the boiler if that doesn't work? Or get a new cold feed sorted (with the possiblity of a new cold feed to a power shower in the bathroom - which would leave the boiler doing heating and bath water).

I'm happy to do any flow rate tests people suggest. I've got the manuals if anyone needs any figures to help give me more advice.

It's my understanding that if the thermostatic valve is plumbed in backwards with a big different in flow rates then it won't work properly, is this right?

Thanks in advance.

What make of shower is it? A built in or exposed?

It's a bathstore.com one, it's the exposed type fixed to two pipes that stick out from the wall.

It's from bathstore.com and it's exposed.

heppers wrote:It's my understanding that if the thermostatic valve is plumbed in backwards with a big different in flow rates then it won't work properly, is this right?

heppers wrote:It's from bathstore.com and it's exposed.

Generally if a shower is plumbed up reverse there will be no temperature control at all. Turn it up slightly and it goes red hot. Turn it down and it goes stone cold.

The hot feed is on the left side normally so turn the shower on full hot and try and see if either side of the valve gets hot. It is only a guide though as some work in reverse. Check the handbook if you have one.

If ur hot water to all the other taps is hot and stays hot that discounts ur boiler, if the shower was/has been working fine since 2007 plumbing ok. It is common that the thermostat heads go on these showers, i would suggest ur best and cheapest option is to change the thermostat head on the shower.

plumbbob wrote:

heppers wrote:It's my understanding that if the thermostatic valve is plumbed in backwards with a big different in flow rates then it won't work properly, is this right?

heppers wrote:It's from bathstore.com and it's exposed.

Generally if a shower is plumbed up reverse there will be no temperature control at all. Turn it up slightly and it goes red hot. Turn it down and it goes stone cold.

The hot feed is on the left side normally so turn the shower on full hot and try and see if either side of the valve gets hot. It is only a guide though as some work in reverse. Check the handbook if you have one.

The pipe on the right gets hot which suggests they are plumbed in wrong which could explain why the shower has never worked 100% as expected from day one.

Cheesie1 wrote:If ur hot water to all the other taps is hot and stays hot that discounts ur boiler, if the shower was/has been working fine since 2007 plumbing ok. It is common that the thermostat heads go on these showers, i would suggest ur best and cheapest option is to change the thermostat head on the shower.

I think that's the best thing. The shower hasn't been right since day one (poor range of adjustment) but now there is no adjustment, it's just like a mixer controlled by the boiler.

The hard thing is finding a plumber that doesn't want to try and fit a new boiler!

heppers wrote:

Cheesie1 wrote:If ur hot water to all the other taps is hot and stays hot that discounts ur boiler, if the shower was/has been working fine since 2007 plumbing ok. It is common that the thermostat heads go on these showers, i would suggest ur best and cheapest option is to change the thermostat head on the shower.

I think that's the best thing. The shower hasn't been right since day one (poor range of adjustment) but now there is no adjustment, it's just like a mixer controlled by the boiler.

The hard thing is finding a plumber that doesn't want to try and fit a new boiler!

Before you waste your money it might be worth checking it is plumbed correctly. Unfortunately, it not an absolute rule that the cold is on the right just 95% of showers are.
Check the installation guide. If you don't have it, search on-line.

IF the boiler temp was set at a showering level you would not have noticed the fault other than the water would have been warm or stone cold with no adjustment between.

HI Heppers

Just a quick thought, if you ok at weilding a spanner and screwdriver, you could remove the mixer from the wall and pipes, flip it over just to check to see if the H&C pipes are reversed.

First isolate the feed pipes to the shower (local isolation valves or failing that mains stop cock. Drain off all the water from all pipework above the shower valve (open up shower valves and then downstairs hot and cold taps to sink)

Just for safety put something robust below where you are working to make sure that if you drop the valve it wont damage the bath, a small sheet of ply across the bath or shower tray would do, dont think a dust sheet will protect, it wont but do put a cloth under the board to prevent board from scratching plastic

remove hose to shower head, undo the two compression nuts from the valve to the pipes, get an allen key and unscrew the grub screw attatching the mounting ring to the valve, get ready to catch the valve, remove the valve from the wall, flip the valve over and reconnect it to the pipes, (if you want you could connect a temporary flexible connection to each exposed pipe with a valve then turn on the supply and see which one is hot and cold.

If valve works ok you have found your problem, then its down to see if the shower can be run permanently in that orientation, if not then you will need to alter the connections and swap them over.

You may be able to access the pipes under the bath, just put in new pipework so each one serves the right side of the shower valve (use push fit fittings as its easier and quicker.

Or get a new shower that has the ability to run in any orientation

Hope this helps

Russ

It might be worth knowing that Bathstore brassware is Crosswater rebranded. You should be able to ID and get instruction for the appropriate Crosswater model.

Hope this help