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thebullettrain

Original Poster:

812 posts

124 months

[news] 
Saturday 6th February 2010 quote quote all
I'm currently buying a 1950s house. However, it has an old boiler in the garage, a water tank in the loft and some water tank (of some descript) in the main bedroom. I've come across the loft water tank and boiler before but the concept of the third cylinder. Does anyone know what that Is about?

I had a quote to have them pulled out and replaced with a combi boiler and the builder sad around £4,000 including changing the pipes but excluding the new boiler purchase.

I'd like to know, please:

what is the two tank and one boiler concept?

Once I replace it would it be best to replace all the pipes or just pump some solution in the boiler to clean the pipes?

Is the quote pretty reflective?

The old boiler flute contains asbestos , is some special treatment required when removing it?

Thanks PHers! I've tapped this up on my iPhone so excuse any typos.

B17NNS

12,494 posts

132 months

[news] 
Saturday 6th February 2010 quote quote all
The 2 tanks in your loft will be a header tank and a cold water tank.

The quote sounds expensive. I would imagine you should be looking at in the £3k-£3.5k region including the boiler.

No need to replace the pipework assuming it all works. But do get the entire system powerflushed.

Re. the asbestos it depends on what kind it is. Not all asbestos is as harmful as you may think (I'd always err on the side of caution though). As long as you can get it out in one piece without damage you can double bag it in polythene and your local tip should dispose of it for you.

Chrisgr31

8,805 posts

140 months

[news] 
Saturday 6th February 2010 quote quote all
A traditional boiler will have a cold water supply tank, a header tank and a hot water tank. When changing over to combi boilers people often fail to realise this means no hot water tank which means no airing cupboard!

It shouldn''t be necessary to rip out all the piping unless it is the wrong size, but a certain amount would need rerooting as the water supply and hot water supply arrangements for a combi are different.

You need to take care with the asbestos, if it is in a sheet form (like a plasterboard sheet) then as mentioned remove it carefully double bad it and take to the tip. If its the sprayed on type you'll need to be very careful. Wear a good quality facemask when dealing with asbestos!

jagracer

7,517 posts

121 months

[news] 
Saturday 6th February 2010 quote quote all
B17NNS said:
Re. the asbestos it depends on what kind it is. Not all asbestos is as harmful as you may think (I'd always err on the side of caution though). As long as you can get it out in one piece without damage you can double bag it in polythene and your local tip should dispose of it for you.
All asbestos is harmful, you only need one fibre in your lungs and it can be curtains later in life. As you say, you need to remove it in one piece and double bag it, wear gloves, disposable overalls and a face mask. and make sure no dust escapes, best way is to damp the area down before hand

B17NNS

12,494 posts

132 months

[news] 
Saturday 6th February 2010 quote quote all
jagracer said:
you only need one fibre in your lungs and it can be curtains later in life.
Asbestos is a naturally occurring mineral found in the rocks in the UK and elsewhere in the world, it is constantly being eroded into the atmosphere. If you take a reading anywhere in the world you will find small quantities of asbestos fibres present. So asbestos fibres would be being breathed in by everyone even if asbestos had not been used by man.
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jagracer

7,517 posts

121 months

[news] 
Saturday 6th February 2010 quote quote all
B17NNS said:
jagracer said:
you only need one fibre in your lungs and it can be curtains later in life.
Asbestos is a naturally occurring mineral found in the rocks in the UK and elsewhere in the world, it is constantly being eroded into the atmosphere. If you take a reading anywhere in the world you will find small quantities of asbestos fibres present. So asbestos fibres would be being breathed in by everyone even if asbestos had not been used by man.
Does that make it OK then?

Simpo Two

59,559 posts

150 months

[news] 
Saturday 6th February 2010 quote quote all
Seems to me that combi boilers are more trouble than they're worth. By a new boiler if the old one doesn't cut it, but otherwise I'd leave it as it is.

Ricky_M

4,612 posts

104 months

[news] 
Saturday 6th February 2010 quote quote all
You should have a large cistern and a small cistern in the attic, the large one feeds the hot water cylinder, the smaller one is the feed and expansion cistern for the central heating.

The hot water cylinder should be a large copper tank in the airing cupboard.

How big is the house? Do you have more than one family and en-suite bathroom? Combination boilers arn't generally well suited to high hot water demands. So check the flow rate of the hot water when selecting a boiler, they can vary wildly.

The pipework does not ussually need changing, although you may need a larger gas supply pipe run to the boiler, all combis I've fitted need atleast a 22mm supply, most old boilers only had 15mm. You'd also need to run a condensate discharge pipe to a drain point and a pressure relief pipe will need running to outside.

So if it is to be fitted in the middle of the house far away from the gas meter and a drain, could be quite a bit of work.

Make sure the price includes a powerflush and you should also have TRVs fitted to atleast the bedroom rads to comply with current regs.

Dogwatch

3,816 posts

107 months

[news] 
Saturday 6th February 2010 quote quote all
Saw an item somewhere that pointed out combi boilers run at mains pressure, so all your radiator circuits will be at that too and should be tested beforehand to make sure the pipework and rads have no weak spots.

A condensing boiler doesn't have to be a combi system. Worcester Bosch and others supply boilers which can be married to existing two-tank systems. I have and prefer the latter as I don't have great faith in the long term reliability of something which strikes up every time someone touches a hot water tap.

Chrisgr31

8,805 posts

140 months

[news] 
Saturday 6th February 2010 quote quote all
Dogwatch said:
I have and prefer the latter as I don't have great faith in the long term reliability of something which strikes up every time someone touches a hot water tap.
Having had to replace an 8 year old combi boiler last year, well in truth it wasn't 8 years old as all components had been replaced at least once and many twice in those 8 years, I'd agree.

Indeed the gas engineer said that "those who say combis are more efficient don't take into account the emissions from our vans as we go and fix them!"

Ricky_M

4,612 posts

104 months

[news] 
Saturday 6th February 2010 quote quote all
The heating circuit won't be quite mains pressure (maybe if you have low water pressure) but they will be higher subject to higher pressure, upto 3 bar if a fault develops, so if you have pipework in concrete floors, re-consider having a combination boiler.

CO2000

2,276 posts

94 months

[news] 
Sunday 7th February 2010 quote quote all
thebullettrain said:
Is the quote pretty reflective?
I'd get another two quotes if I was you (& possibly including one from BG as their recent prices seem to be pretty decent now !)

Ferg

15,242 posts

142 months

[news] 
Sunday 7th February 2010 quote quote all
I'd agree with Ricky.
DON'T fit a Combination Boiler unless you are quite sure that your Hot Water requirements are small enough.
'Mains Pressure' (which no Combination Boiler will supply, in fact) is nothing without a good flow rate if you intend filling a bath or opening two outlets at the same time.

My working week is filled with people who listened to 'experts' and regretted it....

CO2000

2,276 posts

94 months

[news] 
Sunday 7th February 2010 quote quote all
Ferg said:
I'd agree with Ricky.
DON'T fit a Combination Boiler unless you are quite sure that your Hot Water requirements are small enough.
'Mains Pressure' (which no Combination Boiler will supply, in fact) is nothing without a good flow rate if you intend filling a bath or opening two outlets at the same time.

My working week is filled with people who listened to 'experts' and regretted it....
Can you fit a hot water cylinder with a Combi system afterwards if this is a weak point ?

Ferg

15,242 posts

142 months

[news] 
Sunday 7th February 2010 quote quote all
Yes, if there was a cylinder originally, but it would be awkward otherwise as the pipe work would be smaller probably. You'd also need to run something off the hotwater circuit in the boiler. Perhaps just a shower or something.

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