Header tank in Loft constantly over flowing sice having bathroom renovated

[scotjan]

ok thanks. That is something worth investigating; hadn't occured to me that might be there

 

[vanjanflo]

WHPES i would appreciate your opinion- the cowboy plumber fitted one way valves to both hot and cold pipes (i'm told only need them on the cold) but anyway he fitted them to the bath/shower mixer and the basin mixer in the new bathroom in a bid to stop the hot water going up into the CWH tank causing overflow problems etc, but since he has done that the problem with the overflow still happens on and off - when nobody is using any water! and only stops when we isolate the water supply to our other shower - which is situated downstairs. incidentally this groundfloor shower has a pressure reducing valve on it, & is also connected to the rising main but as it is situated downstairs the balance seems to be fine and the shower has always been very good and no problems with temperature control.
cowboy sent a plumber mate round hoping to just get away with putting pressure reducing valves on everything but i haven't let him do this as it feels like more bodging.
can you tell me how the problem has shifted from the new bathroom to the groundfloor one? and what is the solution/remedy for putting it right

 

[WHPES]

For a start, check valves aren't for rectifying design faults.

The balance won't be fine. The mains pressure will vary throughout the day, usually greater in evening when less demand.

Wherever you have a nixer with an unbalanced supply you are going to get problems.

The only way you're going to fix it is to have pressures exactly balanced i.e. plumb the cold in from the header tank.

You could use shower valves for unbalanced systems but you could spend a lot of money and effort and the end result be unsatisfactory.

You would only use PRVs where your shower is supplied from a combi or unvented.

 

[vanjanflo]

thanks for the answers.
this plumber mate of the "cowboy" was trying to tell me the problem cant belong to the new bathroom anymore since the first guy fitted one way valves. he was saying it just cant happen anymore with the valves in place so is a problem with my 3 yr old shower but never the less they were prepared to put valves everywhere!! it just doesnt add up my instinct tells me its bodging and might even cause more problems.

i have a feeling i may have to print this off to use in court so i take it you a registered plumber etc with the knowledge you have... just for "the record". thanks again WHPES.

 

[WHPES]

No, it can only come from a competent person who inspects the installation and sees it first hand. No good quoting any of us from here - on the forum we have only what you tell us. Where in the country are you? Perhaps one of us could inspect it for you? Don't even try printing this off as it will mean nothing without a physical inspection and report.

All being said it is common knowledge that hot and cold should originate from the same header tank. It's normally only with a combi where you may have unbalanced supply issues to address.

If you can find the installation instructions for the shower mixers (or at least obtain copies from the manufacturers) you will find the bit about requiring the pressures to be balanced. That would be the most useful document to find.

 

[scotjan]

Sounds exactly like the solution my plumbers wanted to action. I didn't let them.

How would a combi boiler that they keep suggesting resolve the issue anyway? I suppose that would just be more money in their pockets if I was stupid enough to allow that to be fitted.

The over flow is still intermittent now but I can't ignore it as it has to be fixed. Guess I'll have to get it replumbed and go back to them for compensation via court.

Their website says they are insured and they guarauntee their work for a year but then in the small print it sneakily says that they are not repsonsible and will not gaurauntee work carried out by their own subcontractors. Not sure if that clause is legal but I will find out. Afterall my contract is with the company and I am not responsible for selecting staff to do the job they are.

 

[WHPES]

Under the Supply of Goods and Services Act, the company which invoices you is liable for any work which is supplied through them regardless of whether it is subcontracted or not. The normal way would be you claim from them and then they recover from their subcontractor and not you deal directly with their subcontractor.

However if you paid the subcontractor directly then the issue is between you and the subcontractor,

 

[vanjanflo]

The over flow is still intermittent now but I can't ignore it as it has to be fixed. Guess I'll have to get it replumbed and go back to them for compensation via court.

me and you both! keep me posted on how you get on.. 🙂
i'm no further forward as my "plumbers" idea of putting this right is to stick valves everywhere,😡 i am not prepared to accept this quick cheap fix as it may well not be 100% still and then he would just blame my taps again or my heating system!
quite annoyed with myself for paying him the moment he was finished based on "the look" of the bathroom alone - really should of tried it out for a couple of weeks to know all is working good but we live and learn! 😱

Where in the country are you? Perhaps one of us could inspect it for you? Don't even try printing this off as it will mean nothing without a physical inspection and report.

If you can find the installation instructions for the shower mixers (or at least obtain copies from the manufacturers) you will find the bit about requiring the pressures to be balanced. That would be the most useful document to find.

i am in wakefield west yorkshire.

i got the installation instructions for the shower mixer today but there doesnt seem to be anything stated in it about requiring the pressures to be balanced other than;
1.The product shall be used under the condition of water pressure 0.05~1.0MPa and water temperature 0~90°C.

this is a link to the exact bath shower mixer i have
http://www.plumbfit.com/index.php?prod_id=601&main_fuse=single_product&search_fuse=by_cat

 

[scotjan]

Thanks WHPES I thought it was a bit of a slimy cop out. Anyone can shirk responsibilities by putting a clause like that in but it doesn't make it legal.

I have to say in fairness that the bathroom finish is actually brilliant. Can't fault the tiling. pipe work. Fitted cupboards all look perfect. Its just the plumbing which is kind of a major issue. 🙁

 

[Gurps_24]

Hello all. Sorry for hi-jacking this thread but my plumbing issues seem to be exactly the same. I had a shower fitted downstairs by "professional" plumbers in september 09 and after a few weeks started to notice my overflow pipe dripping with water. It stared to get worse and worse and realised that the header tank in the attic was receiving warm water in from the outlet pipe at the buttom of the header tank. I got advice from people saying to isolate the mixer taps and showers one by one to pin point the issue. Once i isolated the new shower the overflow problem stopped. Now after reading this useful thread i too have noticed that the new shower is receiving cold water from the rising main cold water feed rather than from the header tank in the attic. Can you please confrim that this is the issue? Is the only way around this is to try to get the plumber to re-do the plumbing and get the cold water from the header tank? This has been a nightmare and has taken so long to get to the bottom of what was causing this. I should have visited this brilliant forum ages ago!

 

[WHPES]

I have to say in fairness that the bathroom finish is actually brilliant. Can't fault the tiling. pipe work. Fitted cupboards all look perfect. Its just the plumbing which is kind of a major issue.

A good tiler or joiner does not imply they are also a good plumber.

I wouldn't expect my joiner to rewire my house would I?

You need to get the shower taken off the rising main and connected to a cold feed from the header tank.

 

[emerald]

i found the same problem last week, O/F running, so i went up to the loft, spanner, grips and ball valve in hand, i drained the tank lvl down a few inches only to watch it raise back up, this turned out to be a faultly (integral) non return valve in a concealed mixer shower, luckly it could be accessed and replaced from the front.

 

[buff]

i would have said the coil as burst in the hot tank
bob

 

[mrlennie]

Hmm so would i bob but it seems that the problem is in the mixer showers or taps.

As I understand it they are connected to mains pressure cold water and gravity fed hot water, and are not designed to be able to handle this.

There is a way of blowing out an airlock in a gravity fed system by covering the spout of a mixer tap with a cloth and opening the two taps, the pressure of the cold travels through and forces the water through. The difference with these mixers is that they are mixed earlier than the spout, something which for a shower would make sense and the instructions say do not use on pressure greater than 1 bar.

I am trying to put this together in my mind might have got it totally wrong!

Fitting a combi to correct there mistake is madness. Would not a single pressure reducing valve on the cold side or double check valve sort the problem?