I did a few years ago. Cover off, scrabbling around behind the boiler to find the valve while perched on top of the washing machine !
I remember that - in fact it was probably advice from here :)
The fact I did it, and it has _slowly_ gone back suggests a small leak. For various reasons I have decided this is the time to nail it "properly".
Given that external expansion vessels are hardly hard to come by, it's a source of curiosity as to why boilers have them built in at all.
Sort of job for a multitool. Get some 'filings' but less than with a hacksaw and less strain on the pipe.
Ease of fitting.
Makes it easier then - just one careful hacksaw cut, cleaned up afterwards with a file.
Out of interest, is there something like one of those washing machine tap kits? You clamp it round the pipe and it makes its own hole. It might save having to drain down, thus saving the cost of the inhibitor.
Yup, my go to solution for anything that needs cutting is "impossible" places.
OK! That's inaccessible! As I think others have said, the exact location that you fit it in the circuit is not particularly critical. Mine is about the size of a football (the next size up from the smallest), you need to find a convenient bit of dead space for it. There's no flow, of course (other than when filling) so it can always be fitted with microbore if it needs to be a little distance away from main flow or return pipes (which are probably 22 mm, unless it is a very old installation). Also, mine is actually fitted on a (flexible) filling loop because that was the most convenient way to do it. That way it can be unhooked from the bracket and lowered, making the schraeder valve more accessible for checking/repressurising.
Yes, the clip-on type are a very worthwhile addition to any toolbox!
Personally I wouldn't, in a CH circuit, being a bit more sensitive to debris than something fed from mains pressure. Also, they are not completely reliable.
As luck would have it, there's acres of space next to the boiler in our utility room - mounted up high it would never be seen.
I did wonder, but all the guides online don't suggest it, which is a warning. Also, for the lifetime of inhibitor (5 years ?) trying to skimp on it has "false economy" written all over it.
I did fit one of those kits to add an internal tap to the pipe which feeds the external hose, and found it easy enough.
Rather than actually cutting the pipe, might one of those self cutting clamp things work to tap into a pipe?
I think the work by clamping a metal bracket and seal around the pipe first, then you screw a self hole cutting tap into the bracket.
Just now :)
Dug out the boiler installation and specification book (left by the fitter) and it states that the initial pressure of the expansion vessel is 0.75 bar*. When I hooked up the pump it read 0.50 bar.
I opened a bleed valve on the highest rad with a bucket underneath, and re pressurized to 0.80 bar. Closed bleed valve, and refilled with water to c. 1.5 bar.
Let's see if there is water in the relief valve in a few days.
Of course, now I have done this, May will get back on track, and we won't need the heating till October :)
*I seemed to find loads of US sites that detail this in psi, and FahrenheitHave something to add? Share your thoughts — no account required.
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