Hi all I currently have a BBU behind a Radiant Gas fire in the front living room in my terraced house. I am planning on having a Combi installed, in order to do away with the BBU, and have an Inset gas flame effect fire fitted instead of the existing Radiant. My query is; where in the house is the best place to have the Combi installed? The only Domestic gas supply is into the front lounge which faces the street, with the gas meter in the corner nearest the window, and the aforementioned Radiant fire nearby. Would it be ok to pipe straight up from the lounge, into the bedroom above, and fit the combi there, in say, a cupboard built for this purpose? I know I would then need a flue -probably Room sealed/natural draught one. Also, would I be able to pipe directly from the meter, or would it need another route? I don`t want to be going unnecessarily over the house, routing gas pipes across it, so the direct upwards route seems the be the easiest option.
That's fine as far as pipe routing goes. If you have a boarded loft, then consider putting it up there. Boilers in bedrooms are noisy and distracting.
Most boilers now use fanned flues. These are quite compact and can travel vertically and horizontally for some distance. However, you don't want a flue terminal coming out of the front wall of a house. In a front bedroom, you'd probably want to go up and then backwards slightly and out of the roof on the rear elevation. This would require many flue extensions etc, so it might be better to choose a boiler with the capability of using standard drainpipe as flue parts. Several manufacturers now offer this ability.
Consider running a large gas pipe to your kitchen and installing there. If you do your calculations right, you'll be able to run a gas cooker off it. Gas cooking and a having the boiler in the kitchen rather than a bedroom is likely to substantially increase the value of your home. Many people will refuse to buy a house with electric cooking, or noisy (and perceived as dangerous) bedroom boilers.
You can have the boiler fitted in the loft as long as there is a loft ladder, boarded, a rail around the hatch and a light up there. Being terraced, it will most likely have to be flued through a roof tile, unless you have a gable wall, then through the back. Good combis have integral frost controls.
Otherwise try running gas pipe to the kitchen, if there is apace there for a combi.
I HAD considered running a gas pipe from the front of the house to the rear kitchen, but I think this will either necessitate going under newly-laid wood flooring in the lounge & new carpet in dining area to do this, OR somehow digging outside the house & running the pipe that way (which I think would be a nightmare with Gas/Council, etc), both options which I am very reluctant to do, hence my original question about routing upwards. The loft itself isn`t boarded or anything, but I might have to go that way, and get it legally set up to house the combi, with light/ladder, etc.. Personally, I don`t have a problem with the flue coming out the front wall, but is this something which I may not be allowed to do?
I don't know if there is a general rule against it. However, the plume from modern condensing boilers is visible and would look pretty bad if the front of your house is visible. You'll probably get a caller at the door once a week to tell you that your house is on fire.
At the very least, you'd be better off with a vertical terminal going straight up. This wouldn't be expensive and is less likely to cause a nuisance or confusion in passers by.
In any case, a house with electric cooker, a boiler mounted in the master bedroom and a huge great plume of steam blasting into the street is unlikely to attract potential purchasers when you come to sell.
Best put the boiler in the loft with the flue through a tile, or break into a chimney breast and run the flue up an existing unused chimney flue. Then the hot draw-off pipe can drop into the bedrooms/bathroom and pick up the draw-off there. It will be a win, win, situation as you will have a usable loft for storage.
This is neither necessary nor would it be normal practice. [Only today I connected a 28kW combi to a shortish run of 22mm and the cooker was T-ed from near the boiler.]
If the boiler or cooker make such demands for gas that they effect each other then the gas supply pipe is too small.
About the only time you would run two mains back to a meter is a) For two exceptional large loads probably exceeding 20kW each. E.g. two boilers. b) The appliances were in completely different locations.
Bloor Homes have just finished a development in centre of my village with just this arrangement. Houses 2 feet from pavement, kitchen at front of house and wall mounted glow-worm condensing boiler squirting out steam at just above head height. Actually, even during recent cold spell the plume didn't seem to be too offensive, travelling out about 3 to 4 feet. Interestingly, the flue terminal seem to be offset within the circular air intake, i.e. touching the top of the outer circle and projecting out about 9 inches. I previously posted a query about replacing a non-condensing FF wall mounted boiler with a condenser - the flue is sloping the wrong way for the new boiler. Is the offset arrangement a way to use the existing hole while allowing the flue to slope back towards the boiler ?.
This is perhaps a bit excessive. Most boiler instruction sheets seem to suggest a slope of a few degrees back towards the boiler. Depending on the design of the flue components, lifting the terminal plate slightly to achieve the slope can offset the appearance as you describe.
It really depends on the positions of the flue between the different models.
For example, my old Glow Worm junk boiler was a natural draught type and the hole for the flue terminal was square and centred about a third of the way down at the back so totally within the boiler footprint on the wall.
The new one can take a variety of flue arrangements and has a concentric fitting hole on the top. Into that you can fit a concentric flue system as I have which starts with a 92 degree elbow and then there is a concentric section that plugs into that to form the section through the wall and the terminal. Looking at the outside I can see that the terminal is not quite perpendicular to the wall plate but points very slightly upwards as it should. This arrangement means that the hole through the wall is above the boiler and I had to make good the old hole. Another arrangement that I could have had is an adaptor that fits the top of the boiler and splits the flue arrangement into two separate
50mm sockets to accept 50mm high temperature waste pipe as the flue (similar to Keston)
To be honest, I would figure out which boiler you want to have and then see what the flue arrangement is. It is not a big deal to have the flue in a different position. The 50mm plastic pipe arrangements can be great if you need to cover an awkward situation and direct the vent somewhere else. In a way there is something to be said for having a long flue within the building because a bit more of the water vapour will condense and a bit more heat will be released from the warm flue gases into the building rather than outside.
You hit the nail on the head there, boy.. BTW, thanks for all your comments, some useful, some not. Think I`m going to go for the loft option, tiresome as it is, having to prep the area with boards/light/ladder, etc. Thanks!!
The design of the Condensfit II flue system for the Worcester-Bosch Greenstar does this. It means that if you install the standard horizontal flue with no extensions, then hardly any slope needs to be provided. However, it still needs 0.5 degree upslope away from the boiler and any extensions fitted will mean the full 3 degrees needs to be provided for. I think it is probably more for appearance than anything else.
Consider insulating the rafters to make a warm loft, cold roof situation. This will prevent freezing of the pipes and provide better storage conditions for your new found loft storage area. (As well as reducing your heating bills).
Normal pipe insulation and in-built frost protection in the boiler will deal with freezing in the loft. Making a warm loft will only be for the stored goods, and also make the house warmer too.
I prefer belt and braces myself. I have insulated rafters AND pipe insulation (at least when I've finished, I will). Also, I doubt that pipe insulation will necessarily stop the condensate drain from freezing under pathological conditions.
It would have to be 2m above the pavement or there would have to be a flue-guard over it.
Actually, even during recent cold
I think it is that some manufacturers have this arrangement for their terminals whilst others don't. When cutting a hole for the flue there is a slight clearance this can be used to good effect so as to get the flue to tilt up or down a little as needed by a particular installation.
In general the existing flue would only ever be reused if the exact type of boiler were replaced like for like.
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