Help with an unvented water cylinder please!!!

[highside23]

Please bear with me I have a new born baby in the house and I want to get this sorted so I will try and be as concise as possible.

I have a Heatrea Sadia Electromax electric combination boiler.

The original problem I had when the system was fitted was water hammer every time the toilet was flushed (upstairs only) or a tap was opened fully (again upstairs), the pressure was high then the hammer would happen and the pressure would return to normal. I closed in the stop cock a bit and this helped.

Then months later (a few weeks ago) I noticed the overflow was dripping whenever the water in the cylinder heated up. If I opened the expansion valve on the cold water combination valve (which was very easy to do, like it was a bit open anyway, obviously) the pressure would go and the valve became harder to open. I.e working as it should. I emailed Heatrea sadia and they said check the pressure vessel pressure (it should be 3.5bar) I did there was no pressure and I found a faulty valve. I replaced the valve and recharged the vessel. The water hammer is now back and worse than ever!! (It now happens with the downstares taps too) So I emailed them again and they said that the vessel should be pressurized to match the incoming water pressure. I phoned the water board and they don't know what it is and won't come and measure it.

What can I do to stop it!? I know you can get arrestors to put on the toilet, but it’s not just the toilet that does it. Will opening the stop cock fully help? would matching the pressures really stop the hammer?

Please help!!

 

[lbp plg & htg]

Call back your installer, how old is it?

 

[Koogatubac]

U said u have a combination boiler and a unvented cylinder?
Excuse myself but should you have a heat only boiler for your system?

At the moment all your doing is reducing the FLOW RATE by turning the stop tap down which is NOT solving the problem.

After your stop tap fit a PRESSURE REDUCING VALVE (PRV)
If you say its a unvented cylinder, you should have this in there.

If you can send some pictures it will help ALOT more

 

[highside23]

I installed the system myself about a year ago.

There is a prv in the combination valve.

here is a diagram from the install guide:

 

[PlumbBobBob]

are you qualified to do this work?

 

[highside23]

In a word, no. Im an electromechanical engineer by trade, but like many hands on people, i try to tackle as many jobs as i can myself. Hence asking for a bit of advice on here.

 

[dancinplumba]

do you realise you are dealing with a potential bomb ?? you could be putting your family and your neighbours ives at risk messing with things, gat a G3 qualified installer to check it out IMHO

 

[TBServices]

The only advice you'll get is call someone who's qualified.

 

[GrahamM]

U said u have a combination boiler and a unvented cylinder?
Excuse myself but should you have a heat only boiler for your system?

At the moment all your doing is reducing the FLOW RATE by turning the stop tap down which is NOT solving the problem.

After your stop tap fit a PRESSURE REDUCING VALVE (PRV)
If you say its a unvented cylinder, you should have this in there.

If you can send some pictures it will help ALOT more

Excusing the fact in this instance was carried out by the unqualified OP, a combi can quite safely and happily be linked to an unvented cylinder.

 

[Koogatubac]

O rite, never heard of it graham

 

[Alex Pelton]

Water hammer could be unclipped pipes, unsuitable float valve in the toilet for high pressure, worn taps, incorrect installation on the cylinder etc. Could be a combination of things. Get someone qualified in to have a look. I know that's not the answer you want but better safe than sorry.

 

[TBServices]

O rite, never heard of it graham

Sometimes get the combi running a single tap close by and cylinder supplying the rest of the HW.

 

[Ray Stafford]

Sometimes get the combi running a single tap close by and cylinder supplying the rest of the HW.

It used to be fairly common some years ago when a 24kw or 30kw combi was often quite a lot cheaper than a 24kw or 30kw wall hung boiler. Then the combi manufacturers realised that they could sell their boilers as system boilers by removing the DHW components, and the practice died out.

 

[Blumper]

In addition to the current requirment to be G3 certified to install unvented systems, let alone fiddle with them afterwards, it is a legal requirement for owners of such systems to have them serviced every year by a competent G3 certified person. Is it just me, but shouldn't this forum by all means be offering advice on changing tap washers, bleeding rads etc to unqualified punters, but be far more professionally protective and above all more responsible and steer these enquiries to sourcing qualified tradesmen only..

 

[PlumbBobBob]

good point blumper. we are careful over gas related work and should really be careful with unvented and other safety sensitive systems.

 

[Destroyer2813]

Heres my help, stick to what your good at and let someone who is good and QUALIFIED in out field do this type of work

 

[Koogatubac]

U say you have a new born baby? Stop mucking around with dangerous equipment you dont know and get a professional for the sake of your family!

 

[nicro3]

Or do the course

 

[highside23]

Ok I get what you are all saying, and I do understand why, but I thought forums were to ask questions and get help. Im sure many of you have serviced or worke on your own cars and are not qualified, but if you went on a forum with a problem you would hope to find a solution, no?

 

[SimonG]

Ok I get what you are all saying, and I do understand why, but I thought forums were to ask questions and get help. Im sure many of you have serviced or worke on your own cars and are not qualified, but if you went on a forum with a problem you would hope to find a solution, no?

Here's some good advice, repeated from earlier posts, get a G3 qualified engineer to fix it for you. Your analogy with regard to cars does not hold water. It's not illegal to work on cars, it is illegal to work on unvented cylinders without the necessary qualification.

You won't get any other 'solution'.

 

[highside23]

Fair enough. Are most plumbers G3, or should i just google to find a local one?

 

[SimonG]

Not all are, just make sure you check their card when they arrive. Good Luck.

 

[Simon F]

Fair enough. Are most plumbers G3, or should i just google to find a local one?

if you did a search through the gas safe web page you can see the engineers closest to you. if they are qualified to work on unvented cylinders it will be shown on the areas of work.

Gas Safe Register | Ensure your gas engineer is registered.

Or the CIPHE, maybe other sites

[DLMURL="http://www.ciphe.org.uk/Find-a-Plumber/About-Find-a-Plumber/"]About 'Find a Plumber' - CIPHE[/DLMURL]

other than that it would be a case of phoning around.

 

[PlumbBobBob]

alternatively put a request [DLMURL="http://www.ukplumbersforums.co.uk/im-looking-plumber-gas-engineer/"]here[/DLMURL] putting your general location there may be someone on here local to you

 

[chris watkins]

Just a couple of things on this thread.
1. I agree totally with the consensus not to offer help on this one, although the problem may not have been directly related to the U/C (probable was) the fact that it was not a registered installation should mean that no member should offer corrective advice. I see not difference between this & the gas side.
2. Heatrea Sadia Electromax is a combination unit (not a combi boiler) it contains an un-vented direct cylinder & an electric boiler for the wet central heating. The direct cylinder is normally heated overnight on cheap rate.
3. To my knowledge there is no legal requirement to have un-vented cylinders serviced annually only recommendations from manufacturers ? of course most people would think it wise & economical to have them checked, along with their boiler, every year. I would be most interested if I am wrong on this matter ??????