Megaflow system

[reds]

We are currently renovating a three bedroom terraced house and are being advised by our builder to install a megaflow system, The house will initially only have one bathroom but we plan to convert the loft in the next couple of years so will have a further bathroom there. Any advice on whether this system is crucial will be much appreciated as we are short of both cash and the space to accommodate the water tank.

[keano77]

Why do you need a water tank? Get a combi boiler sufficient to allow for any further loft extension

[KidKruger]

combi should do the trick, I think megaflow is what plumbers recommend for high pressure (by UK standards) shower flow ?

[Dogkennelhillbilly]

Interesting - I'm in v similar position. We have a second floor guest bathroom that no-one ever uses, plus perfectly good gas boiler. Plumber and builder both suggested they (separately) install a megaflo system - architect and I think an electric combo boiler for the top floor would be fine. I don't want to spend ?3000 so my two annual visitors can shower under a pressure washer!

[reds]

Thanks for the replies. Keano77 - I was under the impression that a large tank was part of the megaflow system. Is that not correct??

Dogkennel - is your architect suggesting having two boilers then, one for the loft and one for the rest of the house??

[red devil]

A Megaflo system consists of a large cylinder tank which stores water at a preset temp and pressure. The water is heated via a boiler connected to the mains water and gas supplies. The cylinder can be housed anywhere in the house including the ground floor as it produces it's own balanced pressure. Unlike a combi boiler, there is no drop in water pressure when more than one tap/shower/washing machine etc is being used at the same time. It's particularly good if you have or intend to have high pressure shower heads.

A large 36kw combi (the standard 24kw is used for 1-2 bed flats) is fine for some houses, all depends on your needs and whether constant pressure is important. It doesn't need a storage cylinder like the Megaflo system.

As you will need a boiler with the Megaflo system, why not insert a good quality (Worcester Bosch is worth paying a bit extra for) 36kw combi boiler now, see how you get on with it, and when you come to convert the loft, if you feel the combi is not up to the task of an extra bathroom/shower, simply add a Megaflo to the system then, you should have the space for it in the loft. The one thing you need to double check first though is how far the boiler and Megaflo cylinder can be apart from each other. I don't think it's an issue, but get Megaflo to confirm...

ETA: If you are renovating your house now, future proof yourself and get all the necessary drainage/water supply pipes, electrics/phones/broadband cables etc in place so that they are ready to connect up to when you do the loft conversion.

[Siduhe]

We have a smaller combi boiler and Megaflow tank on separate floors - boiler on the top floor and Megaflow in the middle. It works well for us, but our main bathroom is on the top floor and we're up a bit of a hill so water pressure can be variable - particularly at peak times (or when there's a leak somewhere else in ED), without the Megaflow, we would struggle to get decent water pressure in our main bathroom. I agree it's all about what you need most day to day.

[Mick Mac]

We have had a megaflow in the loft for 10 years, (we don't have a loft conversion) and its been excellent. Allows for high pressure showers / two showers at once etc in a decent sized house. Shower heads and showers are getting much bigger.

It might depend on how much you like a large flow shower head / good shower - some people are happy enough with an electric shower in a loft conversion.

[keano77]

Given the replies above it would seem pressure is the key. I have an electric power shower which doesn't work off the boiler and is fine for my needs. But if you are running showers off your boiler maybe a megaflow is the way to go.

[Jeremy]

I've had two houses with en-suite loft conversions, and a combi boiler has been fine. It does depend on your incoming water pressure of course, but I'd say it's normally only necessary if you want a particularly powerful shower.

[red devil]

keano77 Wrote:

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> I have an electric power shower which

> doesn't work off the boiler and is fine for my

> needs.

I think this is what billy above is suggesting, although happy to be corrected. It's just that a separate electric combi boiler for one bathroom does seem a bit OTT...

[bobbsy]

I have a megaflo cylinder in the loft, and the associated boiler 2 floors below.

The megaflo is great, as red devil pointed out, for enabling constant (well almost) pressure when a couple of hot water taps are being used at the same time. You get mains pressure all the time - but be aware that mains pressure varies throughout the day so there are still periods of weaker pressure. It's expensive to buy, but not massively so. It also has the advantage of having a backup immersion coil so if the boiler breaks, you can still have hot water.

The downside i've found is the "internal bubble" system it uses to absorb pressure fluctuations - does promote some leakage out the overflow pipe. A lot of googling has suggested this is a common problem with megaflo cylinders, and recommend a similar mains pressure cylinder (there are a few other brands) with an external pressure vessel fitted instead.

[Jeremy]

red devil Wrote:

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> a separate electric combi boiler for one bathroom

> does seem a bit OTT...

It wouldn't be a "combi boiler", it would be a simple instantaneous inline water heater.. a couple of hundred quid, and simple to fit.

[red devil]

Jeremy Wrote:

-------------------------------------------------------

> red devil Wrote:

> --------------------------------------------------

> -----

> > a separate electric combi boiler for one

> bathroom

> > does seem a bit OTT...

>

> It wouldn't be a "combi boiler", it would be a

> simple instantaneous inline water heater.. a

> couple of hundred quid, and simple to fit.

I suspect that, and you suspect that, but billy didn't write that. As I said before, happy for him to correct that assumption...

[Siduhe]

@bobbsy, do you recharge the gap in the megaflow? We were told it's best to do this about every 8-10 months to stop any overflow leakage happening. Takes about 10 mins and has worked for us.

[red devil]

bobbsy Wrote:

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> ...(there are a few other brands) with an external pressure vessel fitted instead.

Yep, Megaflo has become the default term for this type of system, when it is in fact a brand name. A bit like Hoover did for vacuum cleaners. I still refer to the Dyson as the hoover...:)

[Dogkennelhillbilly]

Jeremy Wrote:

-------------------------------------------------------

> red devil Wrote:

> --------------------------------------------------

> -----

> > a separate electric combi boiler for one

> bathroom

> > does seem a bit OTT...

>

> It wouldn't be a "combi boiler", it would be a

> simple instantaneous inline water heater.. a

> couple of hundred quid, and simple to fit.

Yes, sorry; that's what I meant (at least).

[bobbsy]

Hi Siduhe,

Thanks - yes, have been doing so, and that does work, but seems the advantage of an external pressure vessel is that you don't need to do this (and a quick require of my original post, can also use a megaflo with an external vessel fitted, doesn't need to be a different brand!).

[alex_b]

We had a megaflow fitted as part of our loft conversion (1 bath and 2 shower rooms) we find it really good and it allows us to run multiple showers at once in the morning. The other benefit with a cylinder is that we have an immersion backup so we still have hot water if the boiler dies for any reason.

My experience with combis is that although they theoretically can deliver the volume of hot water required, they are very dependent on incoming pressure and flow and often don't deliver on the promise.