My neighbour's newly installed (balanced-flue) boiler is installed in a small outhouse and keeps coming on when not required due to it dropping below it's minimum operating temperature.
1) How much ventilation is required in this sort of installation? At present the door is peppered with about 3-4 large vents and numerous drilled holes. The boiler is a "Hero60" incidentally.
2) Would it make much difference if I was to insulate the outhouse for her? Currently it's single brick construction with an uninsulated tile roof. Obviously I could make massive improvements if I was to remove some of the vents and block up the numerous gaps in the doors but would this be safe?
I would like to get a bit of decent advice for her as she is going to be speaking to the corgi bloke who installed the boiler next week and I want to make sure she doesn't get told a load of cr@p.
Unless you want to insulate the whole shed for other reasons, I'd be tempted to build a timber enclosure around the boiler. Make it a few inches larger than the boiler, and lag it with rock wool. Make sure it comes apart really easily for servicing (hinges + latches).
Are you *sure* about that! The installation manual for my Baxi Solo says that ventillation is required for cooling - despite the fact that it's got a balanced flue.
Yes, but not to the extent of several holes in the shed door!
Even with an enclosure around the boiler, as long as there's a bit of a gap between the panels and the boiler, and there's some ventilation to the outside it will be fine. Think under worktop boiler.
This may be because it has a frost protection thermostat and would then be expected behaviour in current outdoor temperatures. It is possible that this thermostat is set too high, of course.
It may also be that there is an issue with the other system controls.....
You would need to refer to the manufacturer's documentation. Presumably this boiler replaced an older conventional flue model and the vents would therefore have provided combustion air. A balanced flue model does not need this but may have a requirement for compartment ventilation. Normally this is relevant if the boiler is a wall mount type in a kitchen cupboard and the ventilation (usually much less than for combustion) is mainly to allow for cooling of the boiler case and so that nearby surfaces don't get too hot.
You would have to check with the manufacturer or look at the documentation for the boiler to be certain, but if the boiler has space all around it, then compartment ventilation is not likely to be an issue.
It should be possible to substantially reduce the ventilation grills or even remove them.
As mentioned you need to refer to installation documentation or call the manufacturer.
As long as the ventilation requirements are met, then insulating the outhouse would be a very effective idea. For a similar type of application in a number of cases I have used 50mm Celotex sheet. This is a polyisocyanurate foam sheet between foil layers and has several times the insulating properties of glass fibre. It's easy to cut and can be put in place on a brick wall using simple studding. You could use plasterboard or ply to cover it afterwards, since the material itself can get dinged, although this is not essential. If you go to the Celotex web site, you will find application notes on how to fix it both to walls and in the roof.
Celotex is relatively expensive compared with glass fibre, but very fast and easy to fit. A sheet of 2440x1220mm costs around £15-18
You could also fit some inside the door since this will be a source of heat loss as well which is probably quite significant.
With this method, you will achieve insulation to the room almost up to current requirements for a house exterior wall.
Some good advice as usual. Managed to get hold of the installation instructions and sure enough no ventilation is required. Draft proofing and plenty of insulation should hopefully resolve the siutation.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.