136 reputation
16
bio website stackoverflow.com/users/37941/…
location London, United Kingdom
age 36
visits member for 2 years, 11 months
seen Dec 13 '11 at 8:04

About Me? Are you kidding? I'm only filling this in for the Autobiographer badge :)


Aug
4
awarded  Notable Question
Dec
23
awarded  Popular Question
Dec
12
revised Can (and should) I replace the hose connecting a cold water expansion vessel to the cold water supply myself?
Update following plumber
Dec
8
awarded  Commentator
Dec
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comment Can (and should) I replace the hose connecting a cold water expansion vessel to the cold water supply myself?
OK, plumber showed me - the valves I have have a twist-to-test red cap. Re 'unhooking' it - it's in a very awkward location behind the boiler and bolted in place!
Dec
8
comment Can (and should) I replace the hose connecting a cold water expansion vessel to the cold water supply myself?
How should I test the TPR valve? (curiosity now - I'm getting a plumber in). I'm not worried about air being in the tank so much as air being in the 'wrong side' of the membrane - the memrane is there for a reason I guess? (why? So it can be mounted water side up is my guess?) How can I fill the tank and drain it? There's no valve immediately after the tank but before everything else - I think I'd have to attach something temporary to do this.
Dec
8
revised Can (and should) I replace the hose connecting a cold water expansion vessel to the cold water supply myself?
added 143 characters in body
Dec
8
comment What's the purpose of a cold water expansion vessel?
Here's what I've learnt: - "check valve" means one-way! - the main section is subject to variable pressure because it gets heated in the calorifier. - I knew the radiator water system is closed. I hadn't understood that the main section is effectively closed too, due to the inlet being a check valve (water under excess pressure can't leave the same way it came in). - hence we do indeed have "a section of closed line that is subject to variable pressure", so an expansion tank is needed.
Dec
8
comment What's the purpose of a cold water expansion vessel?
This would probably also explain why the hose to said expansion tank ruptured - see diy.stackexchange.com/questions/10509/…
Dec
8
answered Can (and should) I replace the hose connecting a cold water expansion vessel to the cold water supply myself?
Dec
8
awarded  Supporter
Dec
8
comment What's the purpose of a cold water expansion vessel?
FWIW I misunderstood "water heater" in your statement to be synonymous with the boiler. I understand your first comment to this answer, but I still don't quite understand your answer - which of the two sane causes, if any, do you think this case falls under? Do the two circuits (main / heating) count as "two devices" ? Also, isn't radiator water always separated from drinking water?
Dec
8
comment What's the purpose of a cold water expansion vessel?
Ah I get it now, expanding hot water from the main section rather than the closed system. That seems consistent with this statement I just found in the calorifier manual: "An expansion vessel is also supplied for connection to the cold supply. Use of an external expansion vessel allows the entire volume of the tank to be used for water storage.". I'm guessing that in the absence of an expansion vessel, the tank has to be designed to be partly empty to leave some 'room' for the water to expand into? theinitiativegroup.org.uk/fscinitiativedatabase/Keston/…
Dec
8
comment What's the purpose of a cold water expansion vessel?
I think a photo will be incomprehensible :) but I might try to knock up a diagram for stackexchange posterity. Does my setup sound quite ordinary?
Dec
8
revised What's the purpose of a cold water expansion vessel?
added 11 characters in body
Dec
8
comment What's the purpose of a cold water expansion vessel?
updated with appliance details.
Dec
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awarded  Editor
Dec
8
revised What's the purpose of a cold water expansion vessel?
added 1044 characters in body
Dec
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comment What's the purpose of a cold water expansion vessel?
I'm not sure I follow. Does "the main section" mean the section connected to the water main? Why would water get forced into the heating system? It's isolated from the mains by a couple of manually operated open/close valves.
Dec
7
comment What's the purpose of a cold water expansion vessel?
Pretty sure the blue tank is not connected to a closed system. It appears to be attached directly to the cold water mains.