Megaflow or Combi???????

[Slugbabydotcom]

Apologies for covering other posts here. I saw the first page and started typing I've posted anyway as I have included more detail

just remember that you dont have to be CORGI'd up to install unvented, just proven competent

This involves doing a G3 course as Tony says, passing a test and being registered with an approved body eg CITB or ERS in accordance with the Water Supply (Water Fittings) regulations 1999 and Building Regulations 1991 part G3 1st June 1992.
If you are not; you cannot fit it or maintain it

Insist on seeing the installers card and make sure the cylinder is maintained annually.

Regulations, sizing and the info that will make you aware that these things can potentially blow your house apart is Here
Skimmimg through it, that document is the best part of the course!

 

[Nige F]

Ah thermostatic radaitor valves -

The plumber I spoke to yesterday (the one fitting his Megaflow) said he'd found some poorly designed pipework.

Why am I not surprised in a "fairly new" house

 

[manwithmission]

Ah thermostatic radaitor valves -

The plumber I spoke to yesterday (the one fitting his Megaflow) said he'd found some poorly designed pipework.

Why am I not surprised in a "fairly new" house

Why's that Nige?

 

[LearnerPlumber]

Freak Out Did We, Its Nearly Summer...!

Good Advice From Good People...! ...thats why I like it here.....

 

[ChrisR]

I think the downstairs rads not heating up is more down to bad plumbing design.

My first thought (for a single one) would be that trv's are stuck, second that the system isn't balanced, the third, sludge. Sludge is common in 12 year old systems where downstairs doesn't heat up properly.

You do need to check your mains water flow- open kitchen plus outside taps and see how much water you get , adding the two, in a minute.

 

[croydoncorgi]

Handyman is going to put an unvented cylinder

In a cellar

.

Hmmmm - tricky. What are you going to do with the tundish and discharge pipe? ('continuous downward slope to drain, etc.')

 

[ChrisR]

You can buy kit to deal with that CC.

 

[Handyman]

Our house is built on a slope. The "cellar" is actually under the front of our house alongside a garage (also under the house). Drains are at ground level which is well below the position where the Range Tribune (not Megaflow) cylinder wil be installed, so no problem with downward slope to drain.

 

[manwithmission]

Well we had the Megaflow installed yesterday.

Bloody hell, I never thought I'd say this, but the Shower is a little bit TOO powerful! It's a nice problem to have of course. Maybe I need to buy a larger Dia shower head so I can get a real deluge without the shower head lifting into the air as it is (a bit) now?

We're absolutely delighted, but now have a couple of problems :

1) The extra pressure means the Shower now drips when off, no matter how tight I close it.

2) A couple of the sinks can't take the pace & turning the hot on now causes a bit too much slashing. I'm going to have to find a way to regulate the flow.

3) Must be unrelated, but the CH pump is now noisy & the engineer said it's on it's way out. It sounds like there's air bubbles or particals in the water. I've been round the rads 20x & bled them, but it doesn't make a difference.


Think I'll have another Shower now

 

[Handyman]

1) The extra pressure means the Shower now drips when off, no matter how tight I close it.

2) A couple of the sinks can't take the pace & turning the hot on now causes a bit too much slashing. I'm going to have to find a way to regulate the flow.

3) Must be unrelated, but the CH pump is now noisy & the engineer said it's on it's way out. It sounds like there's air bubbles or particals in the water. I've been round the rads 20x & bled them, but it doesn't make a difference.

1) A common problem when you push high pressure water through what hitherto had only low pressure water. Answer: Change the washer(s)

2) Check the plug holes and P-traps for hair and gunge. Plug holes ought to be able to cope.

3) Probably correct, although I fitted a new pump on a re-vamped system and it still made odd "particle" type noises. Don't get a cheap pump - get a decent quality one (e.g. Grunfoss or similar)

Can't wait to have ours fitted, but it won't be until August, unfortunately.

 

[manwithmission]

1) A common problem when you push high pressure water through what hitherto had only low pressure water. Answer: Change the washer(s)

2) Check the plug holes and P-traps for hair and gunge. Plug holes ought to be able to cope.

3) Probably correct, although I fitted a new pump on a re-vamped system and it still made odd "particle" type noises. Don't get a cheap pump - get a decent quality one (e.g. Grunfoss or similar)

Can't wait to have ours fitted, but it won't be until August, unfortunately.

1) Is it possible to buy just the washers? The engineer said the insides would be about £70.

2) This isn't the plug holes, it's the basins. The water blasts in so hard it splashes straight out. Believe me, this thing puts out some pressure!

 

[croydoncorgi]

Sorry for any confusion - this reply was really intended for another thread about U/V cylinders.
I was being a bit sly with my provocative question about unvented cylinders in cellars.

The regs demand that there is an effective drain to get rid of WHATEVER comes out of the T&P OR PRV valves on the system. The problem is that the answer is potentially at least lot of water for quite a long time! So you end up with a big sump pump in the cellar capable of shifting (?) 20 litres per minute. But it just sits there, dry, for a long time. And after a while it seizes, so when you actually need it, nothing happens except a blown fuse when the level switch operates, and a large puddle in the cellar!

 

[Handyman]

1) Is it possible to buy just the washers? The engineer said the insides would be about £70.

2) This isn't the plug holes, it's the basins. The water blasts in so hard it splashes straight out. Believe me, this thing puts out some pressure!

1) You must have some serious taps if the insides cost £70 Even replacement quarter-turn ceramic inserts would only cost you 10% of what your man is quoting. More details required before more accurate answer is possible.

2)Fair enough, you'll just have to be more careful In our case, all our cold taps are mains pressure fed (8bar in our case) so we are used to high pressure water. When the new cylinder is fitted, the hot will be boosted from F.A. to 3 bar, and the cold reduced to 3 bar, so should be no problem.

 

[kevindgas]

how many floors does this house have?

i ask because you say that the lower rads don't heat properly pump is probably too small - if it is a 15/50or 15/60 and you have 3 floors it is the first figure 15 means 15 metres max from top of header tank water level to lowest point on system but only if the water content is less than 50 or 60 cubic metres so work it out if you are near to the limits change up to something like a 25/55 or 25/80

 

[mlh07]

hi,
i need help with a similar problem..

getting a loft conversion so the house will be 3 floors with 6 bedrooms and one bathroom on each floor.
really unsure of whether to go for a combi or megaflow. i hear the combi has limited flow rates but could it be possible to install two? (one for upstairs and downstairs...)
or should i go with megaflow? seems like this may be the most expensive option because we'd have to change a lot of the pipes around the house and from the mains water supply ..(something to do with pressure that i didnt understand!)

any suggestions? thanks!