Immersion Heater

[Leoki]

Good morning, i have a multi part question if you have a moment to read and possibly comment.

I have just replaced the immersion heater on a copper cylinder but i had some problems isolating the cold supply. There is a gate valve which i shut and then using a hose pipe i opened the drain cock at the base of the cylinder and water started to drain away however when i started to unscrew the old unit (i did wait about 20 minutes first to allow enough water to drain) water was trickling out so there was water still feeding into the cylinder. I put this down to the gate valve just not closing fully so i then turned off the stopcock, the property is a direct feed but the cylinder still appeared to be filling albeit it slowly. I got the immersion swapped over but the water level in the tank never actually went down more then 3/4 volume.

Now that the immersion bit is fixed the customer has reported the cylinder is leaking from the bottom blanking plug (whoever installed the cylinder used an indirect cylinder so the flow and return are blanked off) so i need to drain the cylinder again and to be able to get the blanking plug off so i can re-seal it.

If the gate valve and the properties stopcock are not stopping the cylinder filling up, am i missing something. I have had a good look around and there do not appear to be any more taps or valves with which i can isolate the supply.

Also being a copper cylinder heated by an immersion, what happens with expansion ?. The new immersion has a thermal cut out (BACKERSAFE) but what happens if that was to fail and the water gets too hot, where would the water expand too, there is no water tank.

 

[carpstu]

go in the loft ad tie the ball valve up so the cylinder stops filling and fit a lever valve so that you can turn off the supply if you carnt find any of turning off the suply

 

[ecowarm]

Good morning, i have a multi part question if you have a moment to read and possibly comment.

I have just replaced the immersion heater on a copper cylinder but i had some problems isolating the cold supply. There is a gate valve which i shut and then using a hose pipe i opened the drain cock at the base of the cylinder and water started to drain away however when i started to unscrew the old unit (i did wait about 20 minutes first to allow enough water to drain) water was trickling out so there was water still feeding into the cylinder. I put this down to the gate valve just not closing fully so i then turned off the stopcock, the property is a direct feed but the cylinder still appeared to be filling albeit it slowly. I got the immersion swapped over but the water level in the tank never actually went down more then 3/4 volume.

Now that the immersion bit is fixed the customer has reported the cylinder is leaking from the bottom blanking plug (whoever installed the cylinder used an indirect cylinder so the flow and return are blanked off) so i need to drain the cylinder again and to be able to get the blanking plug off so i can re-seal it. Will it just nip up?[/B]
If the gate valve and the properties stopcock are not stopping the cylinder filling up, am i missing something. I have had a good look around and there do not appear to be any more taps or valves with which i can isolate the supply. The gate valve is letting by and by turning off the stopcock you will not stop the water from filling the cylinder until the tank in the loft has drained. If you have to drain again turn off stopcock and turn on hot taps to empty the tank and then drain from the drain cock, fit new gate valve while its drained.

Also being a copper cylinder heated by an immersion, what happens with expansion ?. The new immersion has a thermal cut out (BACKERSAFE) but what happens if that was to fail and the water gets too hot, where would the water expand too, there is no water tankB]The thermal cut out is a secondary safety device if the 'stat fails, but to answer your question about expansion it expands up the vent pipe to the tank in the loft. The thermal cut out will prevent any chance of overheating.

[

Hope this helps
Eco

 

[Leoki]

Thankyou for the responses so far. I have nipped the blanking nut just a bit but this seems to have made it a bit worse not better so i have not tightened it anymore. I will check again for a water tank the problem is the property is a masionette with a flat roof, i have asked the owner who does not know what she has by means of services and i have had a look around in all available nooks and crannies for a cupboard that might contain a tank but i just can not find one which lead me to believe that everything is direct fed but then that made me wonder about the cylinder and the fact there must be some facility for expansion e.g a water tank and this would explain why even turning the stopcock off does not stop the water. Its got me stumped but i will make a through check again just to make sure i have not overlooked something really obvious.

Do you think i could get away with closing the existing gate valve (accepting that some water will pass) and fit a new one below it ?

Thankyou to you for your responses so far, i appreciate you giving me your time.

 

[ecowarm]

I have in the passed change gate valves with a bucket under it but I would not do if I can't find the tank! It may be on the roof in a tank room?

 

[Leoki]

Ecowarm, thankyou, i see where you are coming from, i will play hunt the water tank.

 

[Leoki]

Thankyou to those of you who have posted comments so far, you advice has been very helpful. After further checking i found a small water tank at the back of a cupboard area above the bathroom (masionette with flat roof) which i was able to reach after a lot of clutter was moved out of the way. Hot water cylinder drained down and the leaks properly dealt with.

If i may trouble with one additonal question please - The premises is all electric the hot water cylinder heated by the immersion heater as i have mentioned. The cylinder is an indirect type so the primary and return tappings are blanked off with nuts. When i drained down the tank there was water in the coil which please correct me if i am wrong should not be there because the coil is independent of the main tank. Would i be correct in presuming the coil has a hole in it and the volume/pressure of water from the main cylinder is getting in hence the leak from the return tapping in the first place ?

 

[ecowarm]

Thankyou to those of you who have posted comments so far, you advice has been very helpful. After further checking i found a small water tank at the back of a cupboard area above the bathroom (masionette with flat roof) which i was able to reach after a lot of clutter was moved out of the way. Hot water cylinder drained down and the leaks properly dealt with.

If i may trouble with one additonal question please - The premises is all electric the hot water cylinder heated by the immersion heater as i have mentioned. The cylinder is an indirect type so the primary and return tappings are blanked off with nuts. When i drained down the tank there was water in the coil which please correct me if i am wrong should not be there because the coil is independent of the main tank. Would i be correct in presuming the coil has a hole in it and the volume/pressure of water from the main cylinder is getting in hence the leak from the return tapping in the first place ?

That is correct

Eco

 

[Leoki]

Ecowarm, thankyou again for responding. In the grand scheme of things the fact that the cylinder is only operating in a direct mode, e.g its heated by an immersion heater only i take it its a case of wait to see if any other leaks appear on the main cylinder itself, so long as this appears to be sound there is no need to rush into changing out the cylinder ?