Any plumbers on here!? Advice: Unvented Hot Water System??

[535dman]

Not sure if this is the right place to post this but here goes anyway!

Just moved in to a new home and am finding the water system very irritating. The house currently has a gravity system with tanks etc in the loft but the irritating bit is that everything in the house is connected to a very noisy pump (a power shower type of pump located in the airing cupboard). Even if you flush the loo the pump goes on turn any tap on and the pump goes on!

I've called a plumber in and he's advised that to remove the pump from the system (and only connect it to the power shower where it should be connected!)he'd need to re do all the pipework through walls, roofs etc and would cost a small fortune. What he's recommended is to switch off the gravity system alltogeter and install a Megaflow hot water system which he said would cost in the region of £2.5k all in. The house is a 5 bed detached. I wanted to know if the quote is realistic and if the megaflow systems are any good. Someone just told me they are prone to explode if not looked after and can take out an entire side of a house

Edited by 535dman on Thursday 20th December 10:35

[UpTheIron]

Very straightforward to remove the pump from the system without all the work suggested. Result will be lower water pressure, possibly to the extent it is unusable - an hour to fill the bath etc.

Would be fairly quick and easy to test though.

If without the pump your have sufficient water pressure then it is just a case of running the shower off the pump, which would require some work - depending on the layout of your existing pipework this could be a little or a lot. A lot less than £2.5k though!

[535dman]

Thanks - The normal pressure without pump isnt too bad at all but re-doing it without the pump is the issue as all pipes/plumbing go through the walls and under the flooring etc. The Pump and tank are both located within a bedroom cupboard!

[UpTheIron]

535dman said:

Thanks - The normal pressure without pump isnt too bad at all but re-doing it without the pump is the issue as all pipes/plumbing go through the walls and under the flooring etc. The Pump and tank are both located within a bedroom cupboard!

Why do you need to move any pipes? Just remove the pump and mate the pump in & out pipes to complete the circuit, now minus the pump.

[535dman]

Don't have a clue about the pipes mate..thats what the plumber said and thats why i'm on here to find out if he's trying a bit too hard to make me get the megaflow

He's told me it's not possible to remove the pump and re pipe (without going through the floor etc) the way its currently set up. I've got another chap coming to have a look tonight will let you know what he says

[Ranger 6]

Good luck - we've just switched to an un-vented system (not a megaflo, but same principle) as part of our house re-furb and it's brilliant. Low mains water pressure means we've got one with an accumulator, but having switched from a gravity fed system it's light years better.

I do think the doom mongers talking about blowing the side of a house out are exaggerating, ours is working at 1.1 bar according to the guage on the accumulator, you might get a mess, but not on that scale.

[UpTheIron]

535dman said:

Don't have a clue about the pipes mate..thats what the plumber said and thats why i'm on here to find out if he's trying a bit too hard to make me get the megaflow

He's told me it's not possible to remove the pump and re pipe (without going through the floor etc) the way its currently set up. I've got another chap coming to have a look tonight will let you know what he says

The other option could be a quieter pump...I've read of some people taking an approach along the lines of:

1. Bolt pump to paving slab
2. Rest paving slab on several layers of foam rubber / similar
3. Fit box with sound deadening material around pump

[davidd]

We switched to a mains pressure systems a couple of years ago (is that unvented)? Really very good no need for pumps on any of it and the shower is better than a lot of so called power showers I have used in the past.

It added the price of the high pressure tank to the work we were having done, which was about £1k.

I agree with the comment that it should be easy to test without the pump

D

[535dman]

Right - the "other" plumbers been and said the same - can't simply take the pump off - would be cheaper to leave it on and get another unvented system

[UpTheIron]

[quote="Other" Plumber]can't simply take the pump off - would be cheaper to leave it on and get another unvented system
[/quote]Did he say why it can't be taken off? Is silencing the pump, or replacing it with a quieter one an option?

[535dman]

Pipes are the problem - to be honest I'd rather have it removed as it's in a cupboard in a bedroom it sort of wastes the room as it's too noisy at night

[time222222]

Hi , We ve had a mega flo for 7 years and it is supurb , constant hot water and good presure.
Defo recommend one
regards
Marcus

[Pickled Piper]

Had an unvented tank fitted a couple of years ago as part of a bathroom refit. Cost about £1500 from memory. We ditched the pump on the main shower and the new tank was fitted in the loft. Retained existing boiler and central heating pump. Pressure is very good throughout the house (four bed with two bathrooms)and no noisy Power Shower pump. The tank installation had to be inspected by local council buildings inspector as it falls under the regs for pressure vessels.

I would recommend it but get a quote from another plumber. IIRC the actual cost of the tank is about £500.

Try posting on P&P. A plumber called Ferg posts on their and has dispensed some excellent advice in the past.

pp

Edited by Pickled Piper on Wednesday 2nd January 11:16

[e21jason]

Hi

If you have a gravity system, you should not need the pump, as the head of of water in the tank will will serve all the taps, just bypass the pump.

The pump should only do the shower nothing else, if the pump is filling the storage tanks then you have a problem.

You can just replace your existing tank with a unvented system and make the pipework mods in the loft to bypass the tank

Jason

PS I design HVAC and Plumbing sytem for a living

[Piglet]

Can I crash this

Dad has replaced his ancient boiler with a shiny new boiler and what he says is a pressurised central heating system (this may not be relevant!).

He has a big old hot water tank in the loft and a very manky cylinder in the airing cupboard - he wants to get rid of the tank in the loft to convert the loft, he has good mains water pressure and is building an extension so will have 4+ bedrooms to feed (bungalow with 2 storey extension).

Am I right in thinking that what he needs is an unvented indirect system which will replace his old manky airing cupboard cylinder and will remove the need for the tank in the loft? I also think this will give good water pressure throughout the house as long as he has a new cylinder that is at least 210 litres in size?

Second question - his bungalow faces due south and gets lots of sunshine - it seems a perfect candidate for solar panels for hot water, I understand that this would involve the same system as above but with two coils - is that right? If it is right and we don't go the solar panel route now, should we put in a dual coil cylinder now so that we can add solar panels when it all gets a bit more efficient?

Thank you!!

[Nightmare]

Piglet said:

Can I crash this

Dad has replaced his ancient boiler with a shiny new boiler and what he says is a pressurised central heating system (this may not be relevant!).

He has a big old hot water tank in the loft and a very manky cylinder in the airing cupboard - he wants to get rid of the tank in the loft to convert the loft, he has good mains water pressure and is building an extension so will have 4+ bedrooms to feed (bungalow with 2 storey extension).

Am I right in thinking that what he needs is an unvented indirect system which will replace his old manky airing cupboard cylinder and will remove the need for the tank in the loft? I also think this will give good water pressure throughout the house as long as he has a new cylinder that is at least 210 litres in size?

yes...you're spot on. Just done exactly this as part of our extension and getting rid of all the tanks in the loft is cool.

piglet said:

Second question - his bungalow faces due south and gets lots of sunshine - it seems a perfect candidate for solar panels for hot water, I understand that this would involve the same system as above but with two coils - is that right? If it is right and we don't go the solar panel route now, should we put in a dual coil cylinder now so that we can add solar panels when it all gets a bit more efficient?

havent done this but recently looked into it....again you seem to be dead right....and i think worth installing the dual coil in advance as you suggest. A solar collector seemed a better bet than panels mind.....

cheers
Night

Thank you!!

[Piglet]

Cheers Nightmare, I'll look at solar collectors to see what the difference is to panels