Any plumbers on here?

[ukgooner]

I have a question regarding Combination Boilers & Mega-Flow systems

Let me know and I will go into more detail

Cheers

[gettin2dizzy]

there's a few plumbs on here.

hth

[dirtydog]

Yeah go on then, what's up?

[ukgooner]

We are in the process of having a loft conversion, we were going to have a mega-flow system installed but the original plumber has personal issues and cannot do the work, so the builders found another plumber. He came around on Tuesday to price up the job but said that the mega-flow would not give us any benefit over a combi. At present we have a traditional boiler / expansion system with a hot water cylinder in the airing cupboard.

My very limited understanding of a mega-flow is that you get better pressure and have more scope when two or more things are using the water, for example a bath running with the shower on at the same time.

So I just need to know if he is talking cr*p for some reason.


Cheers

[dirtydog]

Basically a mega-flow system is an unvented hot water system. Using one will give you better hot water pressure at the outlets as the cylinder is pressurised but it will depend on the water pressure coming into the cylinder. Whereas a normal cylinder works under atmospheric pressure. Are you looking at getting a combi boiler and the megaflow or a conventional boiler and megaflow?

[ukgooner]

Conventional boiler, keeping what we have, and the megaflow to replace the header & immersion tanks.

The plumber started by saying that we have quite a high mains pressure, but he only held his thumb over a tap, telling me he could generally hold about 1.5 bar but could not hold ours. We are very confused as we are looking at spending about 3k on this and obviously want the correct system.

[dirtydog]

pm'd

[BigBaddad]

Be careful....if you are only upgrading the boiler and leaving in the original rads and pipe work...you may have issues. The higher pressures involved with a combi boiler may cause leaks, or in extreme circumstances, might cause radiators to burst. Sometimes they have rusted through on the inside. Find out what the safety valve is rated at on your new boiler and have your system pressure tested to at least that.

[ukgooner]

I am going to go for the mega-flow as it works out the same cost as replacing my current boiler with a Combi.
In regards to the pressure, should the plumber not testt his as a matter of course?

Cheers

[dirtydog]

In regards to the pressure, should the plumber not testt his as a matter of course?

Cheers


Well you would presume so

[Orpheus]

The main thing you will get is an increased flow rate with the Megaflo, or unvented system, giving you a better shower etc.

Yeah, obviously that is a terribly inaccurate way of testing the mains, this will need to be done properly.

[BoltonSte]

just thought I'd hijack this one if you don't mind?

My radiators have a temperature gradient of hot at the top to cool st the bottom, anyone know what's up?

Runs off a combi I'm guessing installed in 98 (radiators could be older) I've bled them when cold but it's made no difference, what's the cheap remedy? As I will be getting a new boiler at somepoint and may redo the radiators as well for more bling.

cheers

Ste

[dirtydog]

Generally if your rads are cold at the bottom means you probably have a build up of sludge in them. As for a cheap remedy you could drain the system down, take each rad outside and shove a hose pipe in one end and run water through them. It may or may not work.
If you're going to get a new boiler in the not too distant future then just wait till then and replace the rads at the same time. If you're not going to replace the rads and pipes then you'll need to get the system powerflushed before fittin gthe new boiler anyway. Power flushing will set you back about a few hundred quid at least, i think british gas charge about ?600. the problem with that is if you powerflush an old system it may spring leaks all over the place and have to replace the rads anyway

[BoltonSte]

Yeah I had a feeling it would be something like that, do any of the anti sludge chemicals that you can buy work or are they really just as a preventitive?

It'll probably be another year or two before I get round to changing the boiler.

Ste

[dirtydog]

Yeah I had a feeling it would be something like that, do any of the anti sludge chemicals that you can buy work or are they really just as a preventitive?

It'll probably be another year or two before I get round to changing the boiler.

Ste


The anti sludge chemicals you get are only really preventatives, they're corrosion inhibiters.

You can buy system cleaners but how effective they are i don't know, it will depend on the level of sludge in your system

[Orpheus]

Aye, sludge in your rads.

You can buy 'de-sludgers' and whatnot, you'll need to put them in, leave for a while, then drain down, then re-fill with inhibitor.

If you are getting a boiler replaced on an old system they should powerflush the system anyway.