Megaflow and CH installation

[patman209]

Hi all

Looking at having a new CH system (10 rads), 22mm pipes, 15mm tails, valiant ecotec 637 and Megaflo (Sadia) 210 ltr tank installed.

Firstly, Appreciate that Sadia is the leader in Megaflow but also comes in at the most expensive.
Has anyone on here has experience of both Sadia and for example Ariston or Main and can comment on the performance, reliability etc as there is quite a large price difference between Sadia and the others?

My next question - I need to get the mains water pipe coming into my house upgraded to 25mm poly.
The previous owner appears to have has part of it upgraded to poly 25mm at the pipe under the kitchen sink is blue but the flow rate is so poor that the whole pipe cannot be 25 mm.
Has anyone used these companies that use a mole to replace this pipe?
I have made enquiries with a few companies and am awaiting calls back but am wondering if anyone can tell me what they paid. I think I have about 18m from the connection point in the street to my pip under the kitchen sink.

cheers

 

[Agile]

Expect about £600-£800 for the moling and about £400 for the Water Co to connect to the street.

Best get it in 35mm as cost is minimally more.

But why on earth have you "chosen" a 37 kW boiler?

Do you really live in a 12 bed house???

Dont you trust a competent installer to advise you?

Tony

 

[Dan Robinson]

Sounds like another expert specification

 

[hansthebear]

agile i could show you some 5 bed houses in edinburgh with 40kw heat losses...........but that must be unpossible!

 

[patman209]

Thanks for replies.

Agile - I didnt actually say I had "chosen" a 37KW boiler. Its what I said I was "looking" at having installed after taking the opinions of a couple of Corgi heating engineers that visited my property.
One of them even told me that running the pipes in palstic was much better because it was easier for him to do. Corgi badge dont seem to be worth much.
Thanks anyway for the guideline on moling costs, seems pretty high at over 1k all in.

 

[Dan Robinson]

Corgi badge dont seem to be worth much.

Especially as it is Gas Safe you need to be looking at - not that it is worth much more in regards to engineer quality.

One of them even told me that running the pipes in palstic was much better because it was easier for him to do.

Easier = quicker = cheaper. Which when you baulk at a grand to use expensive specialist equipment is not necessarily a bad thing.

Sadia aren't the leader in Megaflow. they are the manufacturer. And they certainly aren't the leader in unvented cylinder manufacturer.

 

[patman209]

I have lived in a property which had plastic push pipes and came home one day to find water spewing from the ceiling and onto the kitchen floor.

Anyhow, I have a couple of moling companies comeing round to visit and provide quotes - will post them up here once I have them for future reference for ayone else that may be interested.

 

[Dan Robinson]

If they are fitted properly they are fine. Not pretty - I grant...

 

[patman209]

correct - not pretty. I immediately turned off the water at the stopcock, but the damage had been done. The chap I had round to fix it reckoned the water had been escaping from the pipe for anything up to 6 hours.

Anyhow he replaced it and never had any issues since.
One of the chaps I had round to quote me for megaflow (different propertty) said taht plastic was not a good idea because if the pipe freezes, the water backs up and the pressure forces the pipe apart at the joins.
I guess everyone has different opinions of what mateirals are best for the job.

 

[Dan Robinson]

Different aspects have different materials better suited.

On the line of pipes freezing with plastic - the flexibility of the plastic would make it better suited as the pipe would expand rather than fracture.

The stresses at the joint whilst higher than normal, would be far lower than with a soldered fitting.

 

[patman209]

I have now had 3 estimates for the water pipe replacement - for a run up to 15m (which mine is) the estimates came in at $695, £880 and £945.
My water company say they can replace the pipe up to the boundary of my property.
Also had a quote for the megaflow described above - £8700 using Sadia 210 ltr tank, vaillant ecotec 637.
Includes 9 rads (single panels), 4 towel rails and TRV4's. Heating engineer estimates 3 bundles of 22mm copper pipes needed. Is this reasonable?

 

[D_Hailsham]

Also had a quote for the megaflow described above - £8700 using Sadia 210 ltr tank, vaillant ecotec 637.

As Tony (Agile) asked earlier: Do you live in a 12 bedroom house?

The Vaillant 637 supplies up to 37KW, which should only be necessary on a very large house.

Use the Whole House Boiler Size Calculator to find the correct size boiler for your house.

 

[patman209]

No its 3 bed, as I said earlier the heating engineer said this was what he recommended. When I asked if 37KW was necessary he said a 31KW boiler would probably suffice and result in a saving of approx £100.

I will use the calculator link, thanks.

 

[petit_pablo]

A 37kw boiler is just overkill. It would need down rating to prevent cycling/microfiring issues.

I would suggest you would be looking at a boiler closer to the 20-24kw mark with 10 rads and the unvented.

Sadia megaflo cylinders are well known but not the best. My prefernce is for a tank that has a separate expansion vessel rather than a built in airgap.

 

[patman209]

I am having a couple of other heating engineers to come and give me some advice and a quote on the best setup and then compare to this first one I have had.
What tank do you recommend?

cheers