Worcester Bosch System boiler with vented or unvented hot water cylinder?

[loziv]

Hi

With a Worcester Bosch system boiler (its new just 4 years old and a Greenstar 30CDi ) what is the best set up to have it with an unvented hot water cylinder or a vented hot water cylinder (which is what we have at present) ?

Because we are having problems with the air getting into the shower supply from the pump I think because its draining the hot water cylinder quicker than the cold water storage tank in the loft can replace it with, and the volume of water in the storage tank is not enough to create enough header pressure in the cylinder which is causing the air in the pipes?

Does this sound feasable?

The the other reason why we are now looking at getting an unvented hot water cylinder is because it will get rid of the storage tank in the loft and we can also get rid of the old hot water cylinder in the airing cupboard in the bathroom freeing up space, as the unvented hot water cylinder could be re-sited downstairs in a room where the boiler currently is in the garage.

How much work is this likely to be and what would be rough costs in South Wales, I have also read the plumber needs to be G3 accredited to fit unvented cylinders.

Many thanks
Lauren

 

[PhoenixServices]

Get 3 quotes for fitting the unvented. They need to be G3. Make sure they test the standing pressure, working pressure and dynamic flow of your water main, to make sure it is suitable.

 

[lame plumber]

As above price depends on quality of goods supplied and the work involved, you cant quote over the net, you need to see the property to get any idea of costs involved

 

[loziv]

Thanks is there a way of finding g3 plumbers that are worcester bosch accredited on the worcester bosch website?
also with the 3 pressure tests would they provide this for you on the quote?

You mention quality of goods what is a good high quality spec system that would go with our worcester bosch green star 30cdi?

what other things should I be asking for for a top spec install and kit or at least it should be specified on the quote

Get 3 quotes for fitting the unvented. They need to be G3. Make sure they test the standing pressure, working pressure and dynamic flow of your water main, to make sure it is suitable.

 

[Ch4 plumbing]

You can go on the Worcester website to find accredited installers but not sure if it would tell you if they are G3, could ask.

 

[loziv]

You mention quality of goods what is a good high quality spec system that would go with our worcester bosch green star 30cdi?


what other things should I be asking for for a top spec install and kit or at least it should be specified on the quote

 

[Stanios]

If I were you I would get a plumber with an aim to remedy the air situation rather than installing a new cyinder. It is not necesseraly an undersized tank, you could have a blocked feed to cylinder or shower feed from cylinder thats installed incorrectly. Correcting any of those including upsizing the storage tank would cost you less than installing a cylinder.

 

[greg27]

If I were you I would get a plumber with an aim to remedy the air situation rather than installing a new cyinder. It is not necesseraly an undersized tank, you could have a blocked feed to cylinder or shower feed from cylinder thats installed incorrectly. Correcting any of those including upsizing the storage tank would cost you less than installing a cylinder.

Has the pump been installed properly , i.e flanges on cylinder , that might be why youre getting air into the pump , what pump is it ?

 

[loziv]

Has the pump been installed properly , i.e flanges on cylinder , that might be why youre getting air into the pump , what pump is it ?

Thanks it's a bristan varispeed 50.

It happens either if you have a long shower or run a bath. Then when you try to use the shower then you can hear air in the pipes which you can always tell from the noise from the pump. It can be the case that air will be in the hours or until you run the bath taps and/or run the shower where you see the water spluttering out of the bath taps.

It even affects the hot water tap in the sink.

 

[stevetheplumber]

Much cheaper to fit an extra tank or enlarge the existing one if the pump is draining it could even be a case of a new ballvalve if the old one isnt working fully first i would check that this is the problem go in loft while the shower is running and see if the tank is emptying
if it is i would first check the ballvalve is running fully you could then try a bigger ballvalve
IF THE TANK ISNT EMPTYING THEN IT WILL BE A POORLY DONE PUMP INSTAL

 

[loziv]

I added I pic in an earlier thread, here are some more pics of the cylinder and the tank in the loft.

How do you tell if the ballvalve is working ok, the tank seems to drain ok

 

[loziv]

 

[GrahamM]

Where is hot water feed to shower coming off the cylinder? Pic would be useful.

 

[GrahamM]

Poor fitted hot water feed from the cylinder is prone to drawing in air. A decent plumber will be able to advise on altering pipework and fitting a Surrey flange or similar to prevent the airlocks.

 

[loziv]

Not sure the white pipe from the top of the cylinder seems to be going to the hot tap in another bathroom upstairs.

Could it also be that the shower pump is draining the tank in the loft quicker than it can refill itself causing it to suck in air into the system?

I have added some more pics so hopefully you can see where the hot water is feeding the pump and the hot water taps on the bath

 

[greg27]

the pump hasn't been fitted correctly i.e no flange for hot supply, bristain say in the installation instructions to fit the hot supply to pump using an Essex flange, this has not been done, hence your pump is pulling air from the top of cylinder and will eventually fail all together, it iis quite a poor install all round

 

[Millsy 82]

If you have the shower replied so it is correct and measure the cold water storage cistern to see if it is enough to handle the shower then it could save a bit of money..

If you have your heart set on an unvented (as long as your pressure/ flow rate are correct then they are a better system) there is a few lads on here from South Wales so depending on where you are compared to them they may be able to do it.

 

[loziv]

Thanks all for all your help, I thought as much the pipework is like a spaghetti junction!

It was like this when we moved into the property, but it is very dangerous for the children as they can easily get burned at the moment, when the pump starts playing up.

I suppose I have 2 options -
1. Get the existing shower and pump sorted using an essex flange etc. Are there any other recommendations to the pipework which I think is in a mess and I am not a plumber?

How much roughly should this cost to sort this out in South Wales? The proble I am finding is there are very few good plumbers and lots of what you would call 'white bog men' who just fit simple plumbing jobs!!

2. Get an unvented cylinder and resite in the garage next to the boiler thus freeing up the airing cupboard for a shower cubicle in the bathroom which is what we need really in addition to the bath and more importantly sorting out the maze of pipework, as our hot water pressure at the moment is awful, apart from the shower as it is pumped.

Lauren

 

[Ch4 plumbing]

When/if you get a plumber round to have a look ask them to check the cold feed for the pump, it should have its own feed from the cwsc and it should also be the lowest tank connector!

also ask them to check the gate valves are fully open.

 

[loziv]

How would you measure the cold water storage cistern, this is a new cistern we had installed replacing an old galvanised tank when we had the new greenstar system boiler installed from an accredited worcester bosch installer.

I asked them at the time did we need a new hot water cylinder and they said it was fine, they made a bit of a mess to be honest and they were not cheap which has made be cautious you think they would be spot on if they are worcester bosch accredited.

I live just outside Swansea, South Wales

 

[loziv]

These are the pipes at the back of the airing cupboard, which is a mess I think why are there so many pipes going up to the loft? And the 2 that have been capped off in the pic by the worcester bosch installers - Are these the ones that were going to the old expansion tank in the loft which was removed as we now have a system boiler

 

[Ch4 plumbing]

Accredited Worcester installer doesn't mean they are the best, it just means they fit a lot of Worcester boilers I'm afraid, that's not to say they arnt any good.

The best way to find a good, fair installer is to ask around, as you have already said they will need to be G3 to install unvented hot water systems.

 

[greg27]

if u measure length cwsc x width of cwsc x depth of water you should be able to get a good idea of the volume of the cwsc, putting an Essex flange on that cylinder is not going to be a very nce job at all, Im in Cardiff but off wrk at the moment

 

[Ch4 plumbing]

Yes, system boilers are sealed systems so have an expansion vessel as opposed to a feed/expansion tank (loft)

 

[loziv]

Where would the expansion vessel be? In the boiler itself? As there is not one in the loft or next to the system boiler.

The house did have an old stelrad boiler with separate systems for upstairs and downstairs (is that possible?)

They had to install a non return valve on one of the pipes to the hot water cylinder beneath my daughters bedroom which they said they would normally do on an old coal fire / back boiler system to stop it over venting up into the cold water cistern in the loft? Again hopefully this makes sense?