Accumulator or Upgrade Mains?

[Yogsey]

Hi, can you help.

I having a loft conversion done to turn a 3 bed, 1 bath house into a 4 bed, 2 bath house, currently have a Worcester combi and an mains flowrate of 16/18 litres per min.

I have had three separate plumbers tell me three different solutions to getting consistent pressure and more flow ranging from new 30kw boiler, megaflo and upgrade of the main pipes through to not upgrading the mains and fitting an accumulator, megaflo and new boiler.

Completely confused as I simply want to be able to run a coupe of showers at the same time and not worry about flow/pressure dropping.

The mains upgrade seems expensive and yet I know nothing about accumulators - any advice? Thanks.

 

[ecowarm]

Hi Yogsey
look here.....GAH - Dualstream Mains Pressure Hot Water Cylinders - How Dualstream Workshttp://www.ukplumbersforums.co.uk/plumbing-forum/9667-accumulator-upgrade-mains.html
Eco

Also make sure you get the boiler sized correctly, oversized will be less efficient.
Go for megaflow over combi if you get water flow sorted.
Do your neighbours suffer from poor mains flow rate?

 

[Yogsey]

Hi Ecowarm

Thanks for the link.

No-one else seems to have a problem, but then they don't have combi's.

I take it that the accumulator regulates the flow and pressure regardless of how much water is flowing into the house then. If I go for an accumulator and megaflo would a 30kw boiler be about the right size? Also would 170 Megaflo be OK for a two bathroom house?

Cheers

 

[secret squirrel]

As you can see from the quotes your getting a combi has its limitations. The advantage is space, you have no tanks or big cylinders, if you change your system you'll loose space (unless you go for electric shower)

I looked at a 5 bed 3 bathroom house that was running on a combi! This is apparently what the home owner requested and didn't want an airing cupboard, just wanted a bigger bathroom because having 3 average size bathrooms was not sufficient.

I digress the cheaper solution to there shower problem was to have electric showers installed, this did reduce the flow a little but they were happy. Depends on your needs and budget.

My own system is a system boiler, a 3 bar stuart turner pump and a quite large cylinder (vented) which runs 2 power showers at the same time more than adequate.

A system I installed a while ago was a 4 bed house with a mega flo and system boiler, 1 electric shower, 2 thermostatic mixer showers, again more than adequate.

There are many ways to skin the proverbial cat just depends on your needs and budget etc. Probably all the plumbers you had in were correct....

Don't think my post has helped really but hopefully explained things a little.

 

[ecowarm]

just sized a four bed 2 bath detached house and it came to 12kw.
170l sounds fine for a 2 bathroom house.

 

[Yogsey]

Hi SS

We're lucky enough to have some space in the loft and I understand that the accumulator can go anywhere so maybe this coupled with a megaflo and system boiler will be best.

I don't mind spending the money (especially given its relativeness to the cost of the conversion itself..!!) Had quotes of circa £ 5k to have this combination of work done, is that a fair ballpark figure?

 

[migoplumber]

fairish ball park figure. make sure you ask your installer the right questions and believe in him before you part with cash.
the correct system to go for imho.

 

[oldplumber]

if you want to save and your current combi is ok then keep it and use it to supply hw to one bathroom/kitchen and reconfigure the heating side to provide an unvented cylinder, with an accumalator attached. or cheaper still stick a cw storage sytem in your roof to provide a constant hw supply for your shower, less to go wrong, the old ways still have a place in modern houses.

 

[Bernie2]

Hi Yogsey!

Accumulators are simple things really just a cylinder with a diaphragm in the middle to pressurise the water. They are gas or air pressured one side of the diaphram and water is stored on the other.

They work like a kind of roof space storage cistern/tank does on a traditional system, but on the incoming water main.

They don't increase water pressure, they are intended to keep the mains water flow rate as constant as possible under high demand.

Bernie