Our water tastes rubbery

[LucyS1]

Here they are. Hope they're clear

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[Onetap]

It looks like the cold feed is the pipe at the top right and comes from above. This is run to below beside the hot water pipe. There is no insulation on these pipes, or on any others shown. The hot water heating the cold pipe isn't an unavoidable feature of this, it is down to simple sloppy installation.


The expansion vessel is the grey ball-like thing, top right.

In the 2nd picture down, the silver thing below the label is a quarter-turn isolating valve. It is operated by a screwdriver slot in the top. I think the pipe going from this to the left is the cold supply (drinking water) to below. I think this bit is wrong.

The water pressure in the cylinder will initially be higher than the pressure in the cold mains, due to the expansion of the water in the cylinder and the compression of the air in the expansion vessel. When you open a cold tap, the first few litres of water will come from the expansion vessel. You will only get cold water from the mains when the pressure has dropped. There is usually an equal pressure connection for the cold water on the combination valve (2nd pic down, top right); This connection is after the pressure reducing valve, but before the check valve so that the cold water will not be contaminated by the hot supply.

Re the pipe going to above, from the top centre of the cylinder; is there a hot water outlet above this? A loft conversion?

Ther should also be a 2-port zone valve on the heating pipes, if this is heated by the boiler, which it appears to be. There isn't one shown here, is it somewhere else?

I'd suspect the rubbery taste and the black dots are from the expansion vessel. You'd need to check the air pressure at the Schraeder valve (car tyre type) on top of the expansion vessel. It looks like it may be wedged against the ceiling; is the Schraeder valve accessible?

Interesting location for the automatic air vent (top picture, left, centre) .

I doubt that the installer is qualified to fit these, too many daft errors. Any registration numbers on the heater or the Benchmark documents?

 

[LucyS1]

Thanks for all this - I'm going to get my hubby to have a good poke around in there tonight and answer your questions. If it's not like locking the stable door after the horse has bolted, is there anything we can do now to correct any of the incorrect installation? You're right, pretty sure the plumber wasn't qualified to put this in. He's done a good job on everything else in the rest of the house, but obviously not here...

 

[gremlin16]

You don't know much about them. It is spelt 'Megaflo'.

I must learn to spell "MEGAFLO"

As for not knowing much about them, I know enough not to advice unqualified members of the public how to play with them

For your information i am G3 registered and do know how to safely install, commission and service unvented systems, are you?

 

[WDIK]

Thanks for all this - I'm going to get my hubby to have a good poke around in there tonight and answer your questions. If it's not like locking the stable door after the horse has bolted, is there anything we can do now to correct any of the incorrect installation? You're right, pretty sure the plumber wasn't qualified to put this in. He's done a good job on everything else in the rest of the house, but obviously not here...

dont touch it, its a specialist G3 device, interference could affect your safety.

what does interest me does the hot water taste of rubber?
try running a glass and let it cool

 

[Onetap]

The sequence of the valves on the cold feed should be exactly as on the Heatrae Sadia unvented water heaters; there is a manual here which has a diagram on P3. You need to save a copy, you only get a small image on-line.

http://www.heatraesadia.com/HS/Heat...int 30 and 50 36005720Issue1 .pdf?OpenElement

You'd need to amend the pipework, re-do some of it.
You need to make sure the Danfoss 2-port valve is fitted on the heating flow pipe to the cylinder. I think you'll need to get a registered installer to re-do it. You could start by getting the installation manual from the manufacturers.

 

[gremlin16]

You'd need to amend the pipework, re-do some of it.
You need to make sure the Danfoss 2-port valve is fitted on the heating flow pipe to the cylinder. I think you'll need to get a registered installer to re-do it. You could start by getting the installation manual from the manufacturers.

You think, but you say amend pipe work


I don't think you need a registered installer I KNOW YOU NEED ONE

 

[Onetap]

As for not knowing much about them, I know enough not to advice unqualified members of the public how to play with them

For your information i am G3 registered and do know how to safely install, commission and service unvented systems, are you?

Well, considering that;

a) my first suggestions were, despite the lack of information, pretty much spot on and that;

b) your contributions, so far, have comprised you slagging off my suggestions

and c) you have, so far, been unerringly wrong,

what do you think?

The Unvented Hotwater Storage course is 2 days.

You're obviously quite impressed with yourself for having earned a G3 certificate but, since the rest of my Engineering qualifications ( besides the unvented ticket) took me some 3 years full-time, followed by 4 years part-time study, it doesn't impress me.

This heater could have been installed better by a Polish IT CCC, simply by following the hieroglyphic drawings in the manual, which the installer obviously didn't bother to look at. If you've got any constructive advice that would help her to get it sorted, other than by slagging me off, then speak up.

Otherwise shut up.

 

[WDIK]

when you two have finished squabbling

heres a thought the multi function/combination valve could be passing, causing water to flow back into the cold when a cold tap is run and the taste of rubber is from the diaphram in the expansion vessel.
which by the way should be white for potable water.

and yes I am a G3

 

[gremlin16]

This heater could have been installed better by a Polish IT CCC only following the hierglyphic drawings in the manual, which the installer obviously didn't bother to look at. If you've got any constructive advice that would help her to get it sorted, other than by slagging me off, then speak up.

1 g3 2 Days very good, means nowt.

2 7 years training? well impressed (self praise ect)

3 Slagging you off. true.

if you bothered reading other post, they do advice getting a registered engineer in. You on the other hand cant see the danger you are putting her in.


Now i could be like you and blow my own trumpet, but whats the point
I can prove my qualifications and they sure ain't fast track. Mind you after 32 years on the tools I openly admit that I am continually learning new and modern methods. anything from 8mm -300mm pipe work, gas,oil,lpg,steam and water

As for your G3 comment, possibly fitted more than you will ever see. Non of them causing any problems ( its the way I tell them opps fit them)

So as you politely said you shut up or at least give advice that is not a danger to others.

ps when you going to get round to fitting a second tap

 

[LucyS1]

Thanks - we're not going to touch it (wouldn't know where to start anyway), we just need to get our heads round it before we call anyone in. How can I find a registered person who's qualified to deal with this type of job - what do I need to ask them?

 

[Onetap]

when you two have finished squabbling

heres a thought the multi function/combination valve could be passing, causing water to flow back into the cold when a cold tap is run and the taste of rubber is from the diaphram in the expansion vessel.
which by the way should be white for potable water.

and yes I am a G3

The problem is not that the combination valve (strainer + pressure reducing valve + check valve + pressure relief valve) is letting by; you have a picture. The cold take-off is after the check valve, or the check valve has been omitted.

It is doing what you say, but for a different reason.

 

[Onetap]

Thanks - we're not going to touch it (wouldn't know where to start anyway), we just need to get our heads round it before we call anyone in. How can I find a registered person who's qualified to deal with this type of job - what do I need to ask them?

Just ask if they've got the Unvented Hot Water Storage Systems qualifications. They will have a credit-card sized ID with a photo and number on it, usually issued by the CITB or Institute of Plumbing. NO card, no job. Don't be fobbed off with 'I forgot it' bull.

I'd suggest you get the installation instructions from the manufacturer first, this will show you what is wrong. It is easier than self-assembley furniture, albeit with a bit of pipe cutting, but an astonishing number are installed incorrectly.

The main issue is the cold supply, presently installed after the combination valve. This is usually connected to a port on the combination valve, which comes with this port capped off. It has been connected in the wrong place, causing back-flow from the expansion vessel & tainting of the water, as you have noticed. The other issue will be that any cold water outlets before the combination valve (upstairs?) will be at a higher pressure than the hot supply; this often causes problems with showers.

You also need to check;

1) the correct 2-port Danfoss valve (normally-closed, spring-return; supplied as a part of the water heater) has been installed on the heating system's flow pipe; a 3-port is NOT acceptable.
2) The wiring is correct.
3) The D2 discharge pipe from the tundish is correctly sized, it is correctly terminated and the valves can discharge full-bore without causing a flood.
4) The Local Authority should have been notified of the Installation; a registered installer should be able to complete the form certifying that it has been installed correctly. They may other wise charge you to inspect and certify it (don't know, never done it that way).
5) Confirm the expansion vessel is suitable for potable hot water; there's a label on it.
6) The expansion vessel may have failed, so you need to get it tested and the air-charge topped up if necessary. You need to isolate and partially drain the heater to do this.
7) All the bits listed in the installation instructions have been fitted ( I cannot see a control thermostat for the heating system, but I do see an unconnected fitting which may be an immersion pocket for a thermostat).
7) The rest of the installation needs to be checked over.

You may be able to recover the costs of this from the original installer, since it should have been included in his work.

 

[LucyS1]

Thanks. Am now on the hunt for proper person to do the job in N London. He/she will have some reading to do!

 

[Onetap]

PS The lack of pipe insulation is a separate issue and is just poor installation prectice.

You should also get the Benchmark installation documents completed, you may be asked for them by buyers if you want to sell the house. If you didn't get them, try the manufacturers for blank replacements.