What System?

[jinty]

My sister said she had problems with her kitchen taps . When I checked , I found I had to shut all the water(hot&cold)off.
The cold went off after I turned the main water tap off but I discovered that the boiler was an old system
which did not have pressurised central heating and I was running off the hot water, My sister said she thought there was a tank behind a wooden panelled wall which does not have access and she thought that I might drain the radiators so I stopped and opened up the mains tap. The radiators were ok
so I left everything alone
What I'd like to find out is How this system works and how do I stop the hot water at the tap ?

 

[ShaunCorbs]

Is there a tank in the loft / what type of property is it house flat etc?

 

[steadyon]

1. You can't drain the radiators through a kitchen or bathroom tap.
2. I sounds as if it is what is called an open vented system, and you are likely to have
a. a cold water storage cistern (large tank) - in the loft (CWSC)
b. a feed and expansion tank (small tank) - in the loft
c. a hot water cylinder - in the airing cupboard (HWC)
3. The kitchen taps most likely have cold fed directly from the mains, and the hot from the HWC
4. To shut off the hot water to the tap you need to turn off the feed of cold water from the CWSC to the HWC. (This feed pipe will go into the HWC very near the bottom of it). There are two main ways of doing this:
a. Find a valve on the pipe linking the CWSC to the base HWC and shut the valve.
b. Shut off the cold supply to the house, and run hot tap(s) until the flow of water ceases.

Option a. is better as it wastes less water. Option b. will empty the CWSC, and once this is empty there is no more water to flow into the HWC and force the hot water out of the top of it.

 

[jtsplumbing]

By the sounds of it your only option is to turn off cold water main run hot taps until water stops , when refilling just hope you don't get any air locks, have you looked under sink to see if there are any service valves (Chrome) with screw driver slot, Other question, is this a rented property ? or her own.

 

[jinty]

Many thanks for your replies and information. I'll checkout all these points on my next visit.
I'll let you know how I get one

 

[Maryplumb]

Best to find a valve on the cold feed to the hot water tank if there is one rather than turn off the main and drain CWSC, because as steadyon says it wastes less water and as jtsplumbing says there is a risk of airlocks when you refill.
If the hot water tank really is inaccessible (this is not unknown especially in old systems where the hot water tank was originally fitted near the fire rather than in an airing cupboard) there may be valves on the pipes coming out of the CWSC, perhaps in the loft, or in a bathroom immediately under the loft. If it supplies cold water as well as the hot tank there will be two, try them to see which is which.
If no CWSC (which will mean all cold taps are supplied from the main) then hot water tank may have its own small cistern immediately above it, then you would have to turn off the main and drain it but since you have already tried that and the hot water continued to flow, a large CWSC seems more likely.
Having said that the hot will always take a couple of minutes to stop as it has more pipework to empty, but you should see a gradual reduction in flow.