Megaflow - did you install one in your loft conversion?

[Alessi]

Our builders have recommended we install a megaflow in our loft conversion to increase water pressure to top floor (we have a combi boiler, not particularly high-pressure, but does alright for current first-floor shower). They say nearly everyone ends up doing this to improve water pressure but 1) they are really expensive and 2) don't seem particularly environmentally friendly (more water and more electricity used).

Has anyone NOT installed a megaflow and found that their shower worked OK? I'm not looking for an out-of-body shower massage experience, just want to be able to wash my hair properly!

[DadOf4]

we had this decision to make a few years ago.

our builders told us that theres no way that our combi boiler would drive a shower up in our loft. And it certainly would not drive 2 showers at once

We stuck with the combi in the end (no money left) - and it works fine - right up to the loft. In fact its a very good shower expereince !

Because we have theromstatic valves in both showers, we can (just) run them both at once (although temperature drops a little)

However, we are near Dulwich hospital (relatively low in ED) and, guess, our pressure is pretty good because of this.

So, yes it can work. I guess you need to test for your pressure

However, it is worth saying: in hindsight (and if i had had the money) i would have put one in. Combi boilers (in hard water areas like this) do go wrong and are expensive. I wouldnt expect that they use any less gas than a boiler/megaflow tank

[Jeremy]

We've done two loft conversions, and stuck with the combi boiler in both cases. Not had any problems. But maybe you have low water pressure in your property?

[HunterHtingSolutions]

An unvented system will only give you a better flow rate if you have a good incoming mains flow rate (ideally a minimum of 20 litres a minute). If you have above 10 litres a minute coming in there is no reason why you wouldn't get a sufficient shower although all combis are only one tap operational.

If you installed an unvented system and all of the existing hot and colds are only 15mm diameter then it wouldn't work properly anyway as you should upgrade the hot and colds everywhere and separately to a minimum of 22mm.

Most of the unvented conversions I price up (including a new boiler and controls) are between ?6500-?10000 depending on how much pipework needs to be upgraded... A much cheaper option may be to upgrade your incoming mains supply from the street to 32mm poly pipe. You don't have to dig a 750mm trench anymore I know someone who can dig two holes and mole the pipe to inside the property (normally averages out at half the price Thames water charge)

I would measure your incoming mains flow rate first though..... If you have an outside tap open into a bucket fully for 30 seconds, measure how many litres you get and times by 2 to give you your flow rate per minute.

Kind of hard explaining all of this with text but feel free to call me tomorrow if you need me to explain anything further. FYI unvented cylinders are ultra efficient!

Regards and good luck!

Billy Hunter 07986296453

Hunter Heating Solutions.

[Alessi]

Thank you so much all for these helpful comments / suggestions. We will certainly get outside with a bucket tonight and measure our mains flow Billy! We had a plumber round this morning who thinks our boiler could just about cope so think we will try going without the megaflow. Megaflow really does sound like a serious investment and we?d have to change our boiler (and probably, as you suggest, incoming pipes as well) ? the price the plumber suggested is going to be around 10k and we just don?t have that right now. Plumber also suggested upgrading the incoming mains supply at a later date if we find the pressure isn?t good enough (if so will definitely consider your ?mole? option), and also doing what he can when he plumbs in the shower to prepare pipes for the addition of a megaflow in future if necessary.

In the meantime we will just cross our fingers and hope it's going to be OK...

[Alessi]

oh and husband points out that I should have spelt it Megaflo - apologies! And must be why I couldn't find any other threads on the topic - correcting it here so other people can find it.

[geh]

have combi and water pressure is fine even in loft (unless 2 of you showering at the same time). My experience with the unreliability of combi boilers would however make the choice for me. Unless I had to (space etc) I would never install another combi.

[Alessi]

Update on our installation ? without Megaflo ? it was fine. We kept our combi boiler (Baxi Duo-tec Combi HEC 133 ? not the best boiler but that?s another story). Water pressure is fine although it takes a long time for the hot water to hit the loft in the mornings so I end up running the shower for about a minute before getting in. But that?s certainly not a problem I?d pay 10k to fix. Loving having my first ever stand-up shower which, incidentally, we got via Diamond Merchants on Acre Lane ? can?t recommend them enough, they were great. Thanks again to all for the tips above - we did measure the incoming flow rate Billy as you suggested and it was reassuring.