Megaflo / Pressurised cylinder

[refinnejk]

We have had a new kitchen fitted and water pressure from hot tap is now too low because it is a 'high pressure' tap. Also getting two new bathrooms and would like high pressure for both showers. There seem to be several options but I think a pressurised cylinder sounds like the best solution. Combi boiler won't provide enough hot water for two showers at same time, pump for whole house will be noisy every time a hot tap is used, and a shower pump won't solve tap pressure in kitchen. House is 15 years old. Does anyone have any idea of cost for just a pressurised cylinder and fitting? Do we need to replace anything else such as boiler, pipes? I do have a plumber but he is taking a long time to get back to me and whilst he is good at doing the work he isn't great at the 'sales' side and helping to choose best option. Any other thoughts on this water pressure problem would be appreciated too. Thank you :)

An unvented (pressurised) cylinder can give unsurpassed hot water. However since there is no cold tank you are dependent on the flow and pressure coming into your house from the main in the pavement.

Fill a bucket at your kitchen sink, time it, calculate how many litres per minute you get. Do the same at utility room tap and garden tap if you have one.

If flow and dynamic pressure are poor you would probably benefit from running a new, larger plastic supply pipe to the pavement, in 25mm or preferably 32mm blue plastic.

A large one is usual. A typical 250 litre cylinder weighs more than a quarter of a ton, so preferably put it on a concrete ground floor, and certainly not in the loft.

You can run it off any boiler, including your old one, or a combi, but get one with two electric immersion heaters, one at the top and one at the bottom, then you can have hot water when your boiler is out of action. Sadia and Santon are two good UK makers.

p.s.
I suggest you buy a new kitchen tap anyway. A UK tap, not a flashy stylish import. Bristan are very good.

I love Megaflo. This is our second house with one and when we eventually complete on the next one (which needs a refurb), I shall be getting another megaflo.

My system is pumped (it's enormous two boilers, megaflo). So both boilers are externally pumped as well as hot water flowing to the taps (big house and extremely high ceilings).

Always get a hot water pump. And previous experience with internal pumps in combi boilers has taught me that an external pump helps as well.

You will obv need to get your plumber to check the water main size. It could be old/undersized or furred up so not delivering pressure. Worth a quick check at least.

you should not need a pump for your hot tapwater.

Under unusual conditions, in a large property with long pipe runs, they may be helpful, but will be wasteful of energy.

Thank you both. Sounds like a pressurised cylinder would do the trick but do you have any idea of cost? Also, what am I looking for in terms of litres per minute for a good pressure? Thanks.

20 lpm would be as low as you could reasonably go.

Flow is not the same as pressure. A plumber can measure dynamic pressure (pressure while taps are running) and advise if you can use an unvented cylinder without needing to replace the water supply pipe. Which is not difficult if it just means digging a trench through the garden, but is harder if there are concrete floors and a drive in the way. A labourer, builder or strong handywoman can dig a trench. The water company will inspect it before permitting it to be used, to verify that it is deep enough (usually about 18 inches) unless you use one of their approved contractors. If your old pipe is lead, or leaking, they may have a grant or subsidy for a replacement pipe, or free connection. See their website.

To fit an unvented cylinder, the plumber/heating engineer needs an extra qualification. Not all have it.

We've got a pressurised cylinder (sorry, can't remember how much it was as had it done as part of bathroom refurbs) and it is brilliant

We got a pressurised cylinder fitted 13months ago. Ours is in the loft (nowhere for it to go downstairs and it replaced a large original tank) but sits on a platform supported on two load bearing masonry walls.
We had to replace our lead main due to lack of pressure. We used an approved contractor and he used a moleing machine rather than digging a trench. This was less disruption and cost as we had to run it down 40m of tarmaced drive.
I was very worried about the cost / disruption but now it's done it's one of the best things we did.
Ours we replaced with the boiler & some of the pipe work/rads as it was very old and on its last legs. I am extremely happy with the result (bar a few teething problems as its a big house with huge pipe runs it's been great) especially the showers which are fantastic although now showering elsewhere (hotels/ILs etc) is extremely disappointing .

Thanks for all the advice and information

Following PigletJohns advice for us - we currently have a beautiful trench dug in our long concrete drive

Neither the heating or showers are actually installed yet but even the plumbers have said that I will have wonderful showers despite being on the top of a hill!!! They had to dig through about 8" thick of concrete drive as none of us realised the original drive and been concreted over

Decided to go for a pump for the two showers as I'm too nervous in case we spend a lot of money on a pressurised cylinder then need to dig up drive, or in case we get leaks etc. we have done a lot of work on house over last few months and everything has gone wrong in one way or another!