How Much Does It Cost To Install Central Heating?



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Cost to Fit Central Heating



Job
Description
Labour
1You want a new central heating system in your 1930’s three bed “other house”. The house is completely empty. It has bare floorboards. This will comprise of the following: a mains gas wall hung condensing boiler, 8 rads. with TRV’s, an insulated hot water cylinder with a thermostat, plastic pipework “all round” insulated downstairs, an insulated header tank in the loft; a programmer; a room stat. This will take 2 tradesmen 5 days 
£1750

Plus materials etc. for the above
 £2200
2The same job but with you and the family living there at the same time. That’s the same two blokes but it will take 9 days! (and drive them bonkers) so labour…
£3150

“Labour” at £175 a day (tradesman) £100 (labourer), includes incidental fixings etc. and tipping charges. “Materials” if mentioned, are larger things (a boiler) and stuff only you can choose (tiles etc).  Also VAT must be added all round.
Information on Central Heating Systems
It must have seemed a very modern day when “Mr and Mrs Youngcouple” proudly showed their ageing parents their new fangled central heating system. Unfortunately (as the Monty Python team slowly discovered) the Romans got there 2000 years ago.
By definition, central heating means a heat source in one place with connected heat outlets in other locations around the house. In most cases this means a boiler and some radiators.
There are variations on this theme though such as a boiler and underfloor heating, or a heater and warm air ducts.
The third part of a normal central heating system is the hot water cylinder or “cistern”. This is usually found in the airing cupboard and is not, as some people believe, a boiler. The cold water supply tank feeds this cistern. You found the tank in the loft when your wife told you to go up there and find out what that scratching sound was and not to come down until you had killed it!

Update, or Replace?
For your own and the environment’s sake, the more efficient your system is, the better!
Fuel costs, ain’t going down! If your system is very old, or you have just moved in and have some spare cash (I’ve never had any “spare cash” in my life, by the way), you will save lots of money in the long run if you rip it all out and start again. You will also be warmer!
Take out the existing radiators at the same time. They are inefficient because they are 20 years old and might be clogged up. Those tiny internal corrosion points may actually break through and leak.
System Components and Design
Fuels
Not all systems are fuelled by mains gas, which is the cheapest fuel option. (I didn’t say cheap, I said cheapest). The next most expensive is oil. Getting more expensive in order are coal, LPG from a large tank, LPG from those orange “bottles” you see outside caravans and in builders vans. So, if you’re buying a lovely little holiday cottage, you should ditch the bottled gas and get oil in.

Boilers
There are two types, standard and combination. Both heat the rads. and the hot water.
Standard boilers are connected to the hot water cylinder.
Combination boilers (combis) have no hot water cylinder. This is because the combi boiler also acts like those old fashioned geysers which hung over the bath or sink in those black and white films with Alan Bates in, when no one had any money and everyone lived in a beastly little terraced house up north and wore pinnies and went to work at 4 o’ clock in t’ morning, (I’d better stop, I can feel a Monty Python sketch coming on)!
In other words, the combi provides “on demand” hot water, to all the taps in the house.
Irrespective of which type of boiler your new system will have, by law your next new boiler will also be a “condensing” boiler. These are very efficient indeed because the exhaust gasses also heat the water.
Hot off the press, just invented, the micro-CHP, “combined heat + power” or cogeneration boiler. This boiler, wait for it, also generates electricity and you can sell this to the national grid. I’m not sure about this but I was told by a bloke in the pub that this means you have to have an electricity pylon in your front garden but think of the money rolling in!

Flues (the boiler’s chimney)
Open
Very old boilers, which usually sit on the floor, have metal or asbestos piped chimneys or flues, right up to roof height. They are either visible, or a defunct chimney stack is hiding them. These are called “open flues”. The oxygen for the boiler’s burner is drawn from the room they are located in.
Balanced
Then progress happened and boilers were made to be room sealed. The outgoing exhaust gases and incoming oxygen pass through the house wall directly behind the boiler via a metal biscuit tin sized contraption. A wire cage has to shield these balanced flues which is because they get hot. Many a builder has warmed his hands in the dead of winter on one of these. If you wish, the boiler can now also be hung on the wall or sealed into a compartment, though how will you get to it again?

Fanned
Then the future happened and man invented fanned flues which have a much smaller (usually 4” (100mm) alloy cylinder, sticking through the wall. The positioning of a boiler  is now more versatile as it can be sited on an internal wall with the flue pipe going round a corner on it’s way outside.
Condensing boilers are so efficient and retain so much of their heat, that their fanned flues can be made from plastic! Imagine that, what will they come up with next? I’m just squirming with anticipation.

Hot Water Cylinders
Get the biggest one you can fit in the available space, provided it has the maximum amount of sprayed on insulation possible. Don’t get one without insulation and then try to fit one of those ludicrous red jackets on it.

Hot water from the standard boiler travels in pipes round and round inside the cistern. Then it comes out again and goes back to the boiler to be reheated. This internal pipework is called a heat exchanger. Heated water transfers its heat to the cold water in the cistern without ever coming into direct contact with it. At no point does the water from the boiler and the central heating system mix with the water in the cylinder. If it did you would soon know about it. Central heating water is filthy black stuff. Different metals in the systems (copper, steel, aluminium, cast iron, brass etc.) react with each other and with the chemicals we put in the system to help it work better.
So, you now have a cistern full of hot water. When you draw some off (plumber speak for turning on the tap), it leaves from the top of the cistern. Cold water from the loft tank then enters the bottom of the cistern, then the heat exchanger heats it and off we go again. Amazingly, it all works by gravity as long as the water company can pump the water into your loft tank. It can then run down through the pipes, then (through you) into the drain, then through the sewer, into the river and back to the sea. How does it get back out of the sea? I must have been away that day!
Radiators
Make sure the installer sizes each radiator correctly to each room. There is a quite complicated formula which considers room position, use, size, window area, floor type, etc. It then tells him the heat requirement that particular room needs to keep you warm. It’s all about BTUs!
If you are having normal looking rads., the chap will then look at the manufacturers charts to see which size of rad. will supply (just a bit more than) the rooms required heat input. That’s the size he will fit.
However, there are some potential complications to consider. The siting of the radiator is pretty important. It used to be the case that they were put under windows, the idea being that draughts would be warmed up as they came in. Not a bad idea. That was before double glazing, which supposedly doesn’t let draughts in. Also if you’re exceedingly posh and have floor length curtains, they trap all the heat behind them. Intended furniture positions are highly relevant, you don’t want a rad. behind the sofa, which will stop the heat, or behind a piano which will eventually bend and crack.

There are lots of variations in radiator dimensions: from 12” to 28” (300mm to 720mm) high, from 12” to 86” (2200mm) long, with a thickness of one or two heating panels, each with or without convection fins. If you are getting tall, thin (vertical) radiators, then width becomes height and vice versa!

This means that if a room requires say 7500 BTU (British thermal units) of heat per hour to keep you warm, this output could be happily provided by maybe 4 different sizes of radiator. Alternatively, you could have two or three smaller rads. whose combined output meets the same requirement. It is aesthetically advisable when you have multiple rads. in the same room to keep them at least the same height, even if the lengths and thicknesses differ.
Problems will arise though. If you want trendy Swedish radiators you could climb up to change the light bulbs from, you won’t get the size variations and the room might just be a wee bit cold.
(I thought the radiator section would only be a couple of lines long… it’s a game isn’t it)!
Controls
The more gadgets there are, the more efficient the system will be and the more money you will save.
How big is your house? If it’s 4 floors and you don’t use the top one unless your “grown up” children descend on you again (when they inevitably realize which side their bread is actually buttered on), it is sensible to “zone”. This allows you to turn on / shut off a whole floor with a flick of a switch.
It’s sensible to fit a frost stat. or even a boiler energy manager if you go away skiing to Gstadt (bless you) every winter.  This turns your heating on (even if its turned off) when the temperature drops to 3ºC.
For the rest of us, the following should suffice….
The Programmer
A programmer which allows the heating to operate at different times on different days e.g. weekends versus weekdays.  It could also set the hot water to come on without the heating.
TRVs
Thermostatic radiator valves (TRVs) on all but one of the radiators. You can set different temperatures in different rooms on a scale of 1 to 6. The radiator shuts down when it has achieved the required temperature. It opens up again when the room temperature drops. This goes on unnoticed for as long as you want. Magic.
There should always be a “bypass radiator“(usually in the bathroom) with no TRV. This prevents all the radiators from turning themselves off simultaneously. The boiler and pump would not know this had happened and would just keep working. The very hot water being created and pumped round (with nowhere to go) is a potential bomb. It probably won’t happen because boilers have internalthermostats and release valves and systems have vent pipes. Still, why trouble them?

Thermostats
Position your room thermostat away from any radiator or direct sunlight. A good spot is adjacent to the front door, where it’s likely to be a bit colder than the rest of the house.
This thermostat will control the whole house’s temperature irrespective of any TRV’s fitted. Fit it in a warm area (a kitchen for example) and it will think the whole house is warmer than it actually is. Consequently, it will turn everything off before the place has warmed up. If you have (two) different zones (i.e. the main living area and then everywhere else), it is essential to have a roomstat in each zone.
The reason why a roomstat is necessary even with TRV’s fitted is to prevent the boiler “over running” via the bypass if all the TRV’s have shut down. This is an unnecessary waste of fuel. Remember, the boiler won’t know the TRV’s are off. In this situation the roomstat will tell the boiler that everything is hot enough at the moment and it can go and have a nice cup of tea.

A hot water cylinder thermostat will tell the boiler when the hot water reaches the temperature you require, which should be 60º C. A thermostat prevents the domestic hot water from heating to the same temperature as that in the boiler and central heating system, which could be as high as 80º C. That that will scald you, never mind the kids. 

Questions to ask the installer during his quotation visit

Are you “Gas Safe” or “Oftec” registered?
Anyone can design and install any type of system including siting and hanging the boiler. However, the person who connects the gas, must by law be “Gas Safe” registered and the person who connectsthe oil must be “Oftec” registered.
Connection will also include commissioning the boiler and testing the pipework which supplies the fuel (not the central heating pipework itself). In the case of an oil boiler it will also include the siting and type of storage tank. Your installer will also check the positioning of the boiler and its external flue. Regulations cover all these aspects and they must be complied with.
What type of pipework will you be using? 
Plastic pipework is common nowadays. It costs more than copper but is much faster to instal and then labour charges become more relevant. However, it doesn’t look as nice so make sure the little pipes which emerge from the floor up to the radiators are still copper. Also, regulations state that all pipes within one metre of the boiler should also be copper.
Do you understand about secondary earth bonding?
Your central heating installer will almost certainly have limited knowledge of this. He should connect all new copper pipework to itself and with existing metal pipework using special earth straps and cable. This is then connected back to the dwelling’s main earthing point.
The idea is this…. If you are touching two metal objects (radiator, boiler, exposed metal pipework, hot water cylinder) and one suddenly becomes “live” for some reason, electrical current will flow through you and you will say “Ow”. This could also happen if you’re standing in a bucket of water! The installer should fit the pipes which connect all these metal objects with earthing cable. Then, the other metal object will also be live and you can quite safely touch it without getting a shock. Don’t try it though!
Current regulations state that in bathrooms (but not kitchens), all components that are electricity conductors (metal bath, radiator, metal water pipes etc), should be connected to each other. They should also connect back to the dwelling’s main earthing point either directly or via the earth block of any electrical source such as wall heaters, shaver point or an electric shower.  This is called secondary equipotential bonding.
However, if you install plastic pipework throughout, this is no longer necessary and may even be detrimental.
Do you know the type of radiators I want?…. Do you know yourself?
Get him to show you three different supplier’s brochures. They all produce different designs of rads. as well as the different sizes mentioned earlier.

Are you sure the boiler is “man” enough for the job? 
If he consults his formula he can add everything up and make sure it is.
A 1930’s, three bed semi will need at least an 80,000 BTU/hour boiler. If it’s a big four bed house, then 100,000.
BUT a new four bed house can get away with a 60,000BTU boiler! That’s modern insulation regulations for you.
Will you be insulating the ground floor pipework (which is under the floorboards)? 
Of course he should. Why heat the foundations? This is a bit difficult though because the pipes run in slots which he cuts out of the joists tops. He should take care not to weaken the joists by cutting away too much. Ideally all cuts should be within 12” (300mm) of a supporting wall.
Decent insulation almost triples the pipes’ diameter and this could be a problem. The installer should add insulation between each pair of joists but this will drive him mad. Customer induced short term insanity is a favourite reason to slap a grand on the price!
You don’t need to insulate pipes under the bedroom floors. Heat loss from these will find its way into the rooms anyway!
 
Job 1 You want a new central heating system in your 1930’s three bed “other house”. The house is completely empty. It has bare floorboards.
This will comprise of the following:
A mains gas wall hung condensing boiler on a nice empty wall with a drain outside; 8 rads. with TRV’s; an insulated hot water cylinder with a thermostat; a three way valve (which allows for hot water in summer but not for heating); plastic pipework “all round” (insulated downstairs); an insulated header tank in the loft; a programmer; a room stat.
You are keeping all the original hot and cold water pipes not relevant to central heating and the supplier is delivering everything to the site.
This will take 2 men 5 days
Day 1 Lift boards, hang rads, hang boiler, fit flue and drain.
Day 2 Fit cylinder and valve, fit loft tank, lay pipework and insulation
Day 3 Connect boiler, connect rads, chase walls for electrics fit programmer etc.
Day 4 Connect cylinder, fit electrics, plaster over,
Day 5 Commission boiler, balance system, refit boards,
Labour £2000 Boiler and flue £825 Controls and valves £225 Electrics £70 Radiators £525 Cylinder and tank £150 Pipework £225 Insulation and plaster £120 Tip and Fixings £45
TOTAL £4185.00

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