Where's my hot water gone..?!

[2520years]

I'm training to be a plumber at College, and I'm replacing a bathroom for the first time.

This is what I did:
I drained the water, re-piped for the new bath and basin, turned the water back on and hey presto, there's no hot water. I've checked the flow and return pipes - they feel hot, but I've felt the hot distribution pipe and that feels cold. I've turned on the hot tap in the kitchen and nothing happens, not even tepid water. I've tried the hot outlet in place for the washing machine and nothing happens. I've tried my new tap in the bathroom and nothing happens.

If I'm right, it's a primatic cylinder (d'oh!) It's got a flow and return, a hot distribution with vent and a cold feed pipe...and no other pipes. It's got an immersion heater wired up too. I can't find an f&e tank. The central heating is working okay.

Is this being caused by a blockage, air or something else? I don't know what to do next. Please could someone give me some direction.

Thanks.

Andy.

 

[TicklyT]

Gate valve on cylinder cold feed jammed shut?

 

[2520years]

Thanks. I'll check when I get there later this morning. I haven't touched it though so I don't think it's that.

 

[ChrisR]

Air lock. Try a search for other posts, but basically connect the mains to a non working tap (washing machine hoses can do it simply) to push the bubble back up the pipe. 10 second bursts.
Sometimes there isn't a mains pipe handy (upstairs hot for example) so an aquavac (£30, Wickes, invaluable, buy one!) on the hot can get it going. If you keep sucking you'll draw air down the vent, but it's worth a try, certainly works usually.

 

[2520years]

I checked the gate valve and it's fine, so I'll give that suggestion a try.

Just to make sure I understand correctly: I need to connect the rising main to the tap that doesn't work, so effectively the water is going backwards, so eventually pushing the air out of the vent pipe. Could I simply connect the two kitchen sink taps and turn on the cold?

Thanks Chris. Can anyone confirm this?

 

[2520years]

Would connecting the cold to the hot in the kitchen blow the air out of the system? I could do with knowing before I buy a hose.

Thanks very much.