Megaflow or Combi???????

[kevplumb]

I get the impression that plumbers down here recommend combis because they are easiest to install when someone wants a new boiler, rather than finding out what the customer really needs for their lifestyle.

You have to know what is on the market. High flow quality combis are very cost effective and do away with unvented cylinder, or cylinders or any kind. Few know of these superb products and fit inappropriately combis. I usually go the combi option as the first line of attack.

Where the main water flow was poor I have found it cost effective to install a cold water accumulator and high flow combi. Customers are delighted with performance.

good idea get rid of the cylinder and fit an accumulator

what a wally

 

[GeorgeBramwell]

I don't understand

This corgikeller666 is obviously a banned person taking another identity. Dangermouse?

He should be banned, until he gains some respect to others. Sad but true.

 

[GeorgeBramwell]

good idea get rid of the cylinder and fit an accumulator

Sad, and he is not improving. A DHW cylinder will not improve water flow rates. An accumulator will. Got it? he may get there one day. We must be positive.

 

[Handyman]

do away with unvented cylinder, or cylinders or any kind. Few know of these superb products and fit inappropriately combis. I usually go the combi option as the first line of attack.

OK, what about the various people around here (elderly, B&B activities, those with children) who want to retain an airing cupboard? Plumber comes along, recommends combi as best solution and hey presto, no airing cupboard, because the plumber didn't bother to find out the cutomer's needs.

We have a very effective 'drying cupboard' heated summer & winter from a small rad on the balance connection on the primary. You can't do that on a combi.

 

[kevplumb]

yeah just keep taking your meds

 

[corgikiller666]

I don't understand

This corgikeller666 is obviously a banned person taking another identity. Dangermouse?

He should be banned, until he gains some respect to others. Sad but true.

yet again you are wrong georgedrivelbumwell, just give up.

 

[GeorgeBramwell]

do away with unvented cylinder, or cylinders or any kind. Few know of these superb products and fit inappropriately combis. I usually go the combi option as the first line of attack.

OK, what about the various people around here (elderly, B&B activities, those with children) who want to retain an airing cupboard? Plumber comes along, recommends combi as best solution and hey presto, no airing cupboard, because the plumber didn't bother to find out the cutomer's needs.

We have a very effective 'drying cupboard' heated summer & winter from a small rad on the balance connection on the primary. You can't do that on a combi.

You can do that with a combi. You can have a two zones and one does a small rad in the airing cupboard and the other the CH. Or better, The Ethos boiler can have a secondary circulation loop kit as an extra. On the return to the combi it can loop around some 22mm pipe at the bottom of the airing cupboard. I have done this using an Ethos.

You can also make your own secondary circulation loop with any combi that relies on a flow switch to activate the burner. A loop from the DHW outlet back the the inlet using two check valves, a bronze pump, cheap timer and a pipe stat. This gives heat in the cupboard and "instant" DHW at all taps, as the taps are off the loop. Have the loop well insulated except in the airing cupboard. The pipe in the cupboard can be off the loop, like a rad, with its own valves. Kills two birds with one stone: instant DHW at the taps and heat in the cupboard. I have done this many times. Customers are delighted as they have a huge airing cupboard.

Easy!!! Do not listen to old wives tales from old plumbers - drains is their speciality.

 

[corgikiller666]

do away with unvented cylinder, or cylinders or any kind. Few know of these superb products and fit inappropriately combis. I usually go the combi option as the first line of attack.

OK, what about the various people around here (elderly, B&B activities, those with children) who want to retain an airing cupboard? Plumber comes along, recommends combi as best solution and hey presto, no airing cupboard, because the plumber didn't bother to find out the cutomer's needs.

We have a very effective 'drying cupboard' heated summer & winter from a small rad on the balance connection on the primary. You can't do that on a combi.

You can do that with a combi. You can have a two zones and one does a small rad in the airing cupboard. Or better, The Ethos boiler can have a secondary circulation loop kits as an extra. On the return to the combi it can loop around some 22mm pipe at the bottom of the airing cupboard. I have done this using an Ethos.

You can also make your own secondary circulation loop with any combi that relies on a flow switch to activate the burner. A loop from the DHW outlet back the the inlet using two check valves, a bronze pump, cheap timer and a pipe stat. This gives heat in the cupboard and "instant" DHW at all taps, as the taps are off the loop. Have the loop well insulated except in the airing cupboard. The pipe in the cupboard can be off the loop, like a rad, with its own valves. Kills two birds with one stone: instant DHW at the taps and heat in the cupboard.

Easy!!! Do not listen to old wives tales from old plumbers - drains is their speciality.

brilliant advice as usual but do the manufacturers allow this? Of course you haven't checked and have no idea as usual. try and google an answer or if that fails just make some flimsys excuse.

 

[Handyman]

mlh07 if you're still bothering to read this: Get a couple of quotes for a correctly designed system giving you the features that you want - not what the plumber wants to fit (because he gets a good discount on a particular combi boiler) or what he thinks you want (because he hasn't asked you what you need). If the Megaflow type system is not too extortionate, go for it. You will appreciate the benefits in the long run - and you can choose whatever brand of compact effecient boiler you want to heat it.

I'm outa here.............

 

[GeorgeBramwell]

mlh07 if you're still bothering to read this: Get a couple of quotes for a correctly designed system giving you the features that you want - not what the plumber wants to fit (because he gets a good discount on a particular combi boiler) or what he thinks you want (because he hasn't asked you what you need). If the Megaflow type system is not too extortionate, go for it.

It has been explained to you and you still can't understand. It is best you stick to DIY.

 

[denvillesman]

I have just stumbled on this thread and loved it so much I just have to add a little resurection!
As a 60 year old DIYer I have seen a few things over the years and what stands out (on plumbing/heating) is the manufacturer/installer driven thrust on combis. I often refer to them them to others as a huge step backwards. Are they basically not just large "geysers", ie 1940's principles (but not lasting as long as they did then)? Providing on demand domestic HW (OK CH as well). On the domestic front rarely has there been such a huge nationwide con on jo public. As others have said here it is all driven by "professionals" with little to no regard for the needs or requirements of the poor innocent customer.

If anyone reads this could they offer some advice on my dripping PRV on my c. 12 year old megaflo. I cannot find a straight answer as to whether I SHOULD replace just the black plastic cartridge (where the leak is) or the whole PRV including the casting (and the cast expansion relief valve?). If the latter, WHY exactly (hopefully not just to add more parts profits for any installer).

And finally, whilst I know all about G3 quals and nuclear explosions etc, is there really any reason I could noit replace said valves myself, if that is the necessary advice.

Yours cynically, John

 

[Handyman]

Excellent! )

As regards PRV, mine also dripped during the summer. The drips came out of the discharge pipe outside. Various people told me I needed a new PRV, which I fitted myself quite easily (whole thing, not just the innards) - but it still dripped from the pipe.

Then, a local guy suggested that it was nothing to do with the valve, but caused by low (or no) pressure in the expansion vessel bladder, so when the water expanded, the valve operated as it should and released the pressure. Solution? Depressurise system, pump up the exp vessel bladder to its specified 3bar, repressurise system, and Bob's yer uncle. Why it lost pressure, I don't know, but it's been OK ever since.

The local guy now does the annual service on my boiler.