heating system for extension

[haribo22]

Hi.
I have had an extension built to the rear of my bungalow and I am ready to install the heating system.
I have carried out some of the work myself, but have got in tradesmen when I needed them.
I do not have a trade, but have done quite a few jobs with a family member (a roofer) over the years.
I have also worked with some of the other tradesmen and have picked up things from them.
I realise that it's not the perfect setup, but when you are trying to stick to a tight budget, it's difficult paying trades to do every little thing.
On the plumbing side, I will be doing all the pipe work (i've done this a few times in the past and will have it all pressure tested) and I will then get a heating engineer to connect the gas, connect all the pipes to the boiler and commission it.
A friend (who has just qualified as a plumber) was at the property last week doing a few things and he told me that I should come off the boiler (for the hot and cold) in 15mm, straight into 22mm.
Would this be of any benefit, seeing as it has to go through the 15mm pipe first.
I then gave him a brief description of the bungalow to him, so he could show the engineer that he uses.
In total there will be 2 en-suites, both with a toilet, basin and shower (run of the central heating). A bathroom with 2 basins, a toilet, a bath and another shower (run off the central heating) and a kitchen with a sink.
He has not been to the property, but have said straight away that a combi boiler will not work and I will have to have a cylinder put in somewhere.
The problem I have is that the ceilings are vaulted, so I don't have an attic space.
Could I just change the shower to electric or would this make no difference.
I am having conflicting advice from a few different people and want to get it right first time.

Thanks.

 

[sambotc]

Hi,

What type of system you you currently have, I assume a combi as you mentioned no space for a tank?

Certainly with 2x en suites and at least 1 other bathroom, a combi is not a good choice, even a big one.
I understand you are trying to keep the budget down, but in this instance I think you need some advise of a good heating engineer. The immediate solution from the info you have provided would be an unvented cylinder and boiler. This would depend on your incoming water main being adequate, also the siting of the unvented cylinder to comply with G3 regulations. The engineer working/installing on the unvented need's to be specifically qualified.

An unvented cylinder mean's no tanks in loft space, ample amounts of hot water to run multiple showers/ outlets and balanced hot & cold supplies which should make the plumbing easier for you to do it DIY.

HTH Sam

 

[darren17]

come off the boiler in 15mm not 22mm
as far as combi goes you can get one
but surely you won't be using all the washing facilites at the one time

 

[haribo22]

Thanks guy's for your advice.

I bought the bungalow some time ago. It was a timber frame with a render finish on the exterior plyboard. I have put an outer skin of block around it with a render finish.
it had a truss roof on it, but I ripped it off to put in the vaulted ceilings and basically all the old stuff inside has been ripped out.
The conflicting advice I am getting is just because I will have 3 showers, a bath, a kitchen sink and 4 basins, they will not all be used at once. However if they were then the water pressure would obviously be garbage.
One engineer told me this and considering that there is just me and my wife it will more than likely be just 2 things using water at once, so there won't be any problems.
However if I sell the house in years to come I will be passing this potential problem on to the new owner.
What is the difference in price between a good combi and an unvented cylinder with boiler.
Also most boilers have the hot and cold coming out of the boiler in 15mm, if I were to go into a 22mm reducer and then run the pipes in 22mm before going into 15mm again to connect to toilets and taps, would this make a difference, or do I look for a boiler that comes out in 22mm.
Thanks.

 

[Agile]

A combi boiler DHW output should be in 15 mm to each outlet.

A cylinder will provide hot water to most of the outlets at the same time IF and only IF there is adequate mains dynamic pressure. Until that is tested you cannot make any decisions.

I do have to say that if you dont use a competent professional to specify the system you have a high chance of messing it up if you just take free advice from non professionals.

Tony

 

[haribo22]

Thanks guy's.
I am going to get a heating engineer to the property next week and take it from there.

Thanks again.