“ Heat output - 30,750 to 120,000 Btu/hr (9 to 35kw). Performance is up to 88% energy efficient. A balanced flue model is also available. this boiler may reduce hot water costs because you heat only the water you use. Optional integral programmer available „
My house came with a disclaimer in the buying contract about its central heating system ? 8 months later I found why?..yes the 25-year old boiler turned up its toes and quite literally went out with a bang. Bust pressure relief valve failed and flooded my poor neighbour downstairs (luckily it was her bathroom that copped it?) My boiler?s age meant that spare parts weren?t even available in the antique shop, never mind British Gas?but some quick studying of the pipes revealed that what I had was an old-fashioned gravity hot water system and pumped central heating ? quite extravagant for a one bedroomed flat, but this lot was put in before the world had heard of that new-fangled invention ? the combination boiler. As the name suggests, the combi boiler combines the functions of a gas water heater and central heating boiler into one box, dispensing with the need for a hot water cylinder, and even the cold water tanks in the loft. Whenever the boiler senses that you have turned on a hot tap, it switches on and hot water will come through in about 20-30 seconds. Only one snag?. Combi boilers only work at high pressure, meaning that connecting one to your rickety old radiators is fraught with leakage risk, and I had already dampened the life of my neighbour once before?..so enter the Worcester 24 CDi The CDi series is one of the very few combi boilers that can run on low pressure ? so therefore you can connect it straight onto your old rads without any problem. You do have to keep the little feed/expansion tank in the loft in order to keep the radiators topped up, but this is not a big problem. The CDi series also has a double plate heat exchanger so that if you live in a hard water area, scaling is not as big an issue as it often is. Another benefit is electronic ignition of the burner ? no pilot lights hissing away all night and wasting gas. There are also separate temperature controls for the hot water and heating. Flueing (the chi
mney) is very flexible on this model, you can go horizontally through a wall, go sideways first and then horizontally, or vertically. The design of my flat meant that I had to go for the more costly vertical option straight through the roof, but again vertically flued combis are actually quite rare ? the Worcester is again right out in front in this area. I would criticise the hot water flow rate ? sometimes if you vary the setting of a tap it suddenly goes cold again before the boiler ?recovers? from the pressure change and starts delivering hot again, but overall this is probably one of the best combis in its class and well worth considering. The guarantee that I got was generous (2 years).
As I have already said in previous opinions, when we moved into this house in July, things were definitely not as they had appeared to be! We had a conventional hot water tank with an immersion heater that worked so we could get hot water, but when we tried the central heating, there was nothing doing. We couldn't get it to work on the timer or by manually switching it on and off. And so it came to pass that the plumber was called. We'd found ourselves a good plumber who had been as part of the group of people building and kitting out the en suite bathroom in mom and dad?s room. He said that we should have a new boiler; either a wall mounted one, or a floor standing one, which would be the more powerful of the two. We chose the wall-mounted version as this would save space in the kitchen, it was the cheaper option and it would be perfectly powerful enough for our needs. The boiler that we chose is a Worcester Combi Boiler 35CDi II. It comes in a standard white metal case measuring 450mm wide, 850mm high and 600mm deep, so it's quite a large piece of kit. Ours is fitted in the corner of the kitchen where an old heating boiler of some description had been. Don't ask me what the old one actually did, if anything, we never worked that one out - as I say it's a house like that!! The cost of the boiler plus the labour for the fitting was £1,650. It took the plumber and his mate about two hours to fit the new boiler and to check all the system and make sure all the radiators worked properly. The hot water is now available constantly, and the boiler is powerful enough for us to able to fill two baths at the same time if we wanted to, although Dave and I usually take showers these days. When the hot water tap is turned on the boiler fires immediately and within a moment or two hot water flows out of the tap, any time day or night. There is a thermostat on the boiler itself
so that the temperature of the water can be controlled. Obviously there would be no need to have the water coming out of the tap at near boiling point, because we?' just have to cool it by adding cold water to it, so we have set it at an optimum level for washing up, bathing etc. There is a central heating timer on the front of the boiler, which is one with the little tappets all the way round corresponding to the 24 hours in the day at 15-minute intervals. By pushing the tappets in towards the centre of the dial you can control what time of the day the central heating comes on and goes off. There is also a switch to turn the central heating on and off manually. We also have thermostats on all the radiators so that, when the heating is on, we can make sure that the rooms we are using are the ones that are the warmest. The boiler itself also has set of indicator lights on it. One is the mains electricity indicator and should always be on, showing that the boiler is connected to the electricity supply to power the pump and the timers. There are two further lights corresponding to the central heating and the hot water, which light up when the boiler is in use. Before the plumber left he handed us a plastic T shaped implement and said he would tell us what to do with it. Well, I did wonder what was coming?? It was actually a key to be used to re pressurise the system. There's a dial on the front of the boiler showing the water pressure and every time it dips below a certain level we will have to insert the key and turn it in order to increase the water pressure to the requisite level so that the boiler will work efficiently. This will happen every three months or so apparently. The added bonus is that we now have quite a good-sized storage cupboard where the hot water tank used to be, as that was removed since it was no longer needed. In conclusion I would say that, although this has been a
big expenditure that we could have well done without I am sure that the efficiency of the new system will mean that it will begin to pay for itself straight away.
British Gas don't make anything. Apart from a ridiculously large profit. This is a Worcester, which has made to a lower specification so that BG can increase it's margin. Worcester make some great combi boilers, like the 28i, but this has had some of the innovative features removed. It's only available from British Gas. It's quite a large thing, and with the mass of pipe work that hangs underneath it, reminds me of a rig in the north sea that the gas came from in the first place. Combi's are ideal for flats and small houses. Get a conventional boiler for anything larger. Combi's in general: Just as the old water heaters (anyone out there have a Triton?) were being phased out, some of which were obviously dangerous, a new challenge was upon us. The powers that be, i.e. Corgi, acting on legislation, decided that some open flued water heaters before a specific date were dangerous, but after that date they were not. It has always puzzled me that a heater installed on the Wednesday was deemed dangerous, yet an identical one installed on the Thursday was safe! Anyway, the reason I mention water heaters, is because that is what 50% of a combination boiler is. Albeit all tangled up with a conventional boiler and covered in a large enamel spayed aluminium box. Except for the Ideal Response, which is rather smaller. By the way, if you are offered an Ideal Response, the ideal response to the question is ?no thanks? I?d rather stick my head up an elephant?s bottom. Trust me, an elephant?s bum is much more desirable. Is a combi suitable for you? Well not if you want more than about eight medium size rads, or you use more than one hot tap at a time. A combo heats the water as you use it, and so is limited to the amount it can heat. It will raise the temperature about 40 degrees Celsius. So in the winter, it may be a case of turning the tap down a bit to get the desired temperature. Wh
ilst it is heating the water, it is not heating the central heating. Not normally a problem, unless you have a dripping tap or two, which could prevent the heating from coming on at all. You must have good mains water pressure. Absolutely essential. Another thing to consider is the lack of an immersion as back up hot water. There are no tanks associated with a combo system, so if it breaks down, that?s it until it?s fixed. It?s not too difficult to install, as there are no tanks, cylinders or many controls to fit. The timer can be an integral part of the boiler. So if you fit thermostatic radiator valves on the rads, all you have to do electrically is wire a plug and away you go. The gas however, has to be installed by a competent person.