Please help, no hot water!

KevinC

Hi,
The hot water has stopped working. I am pretty sure happened after I drained the system to fix a dripping tap. I am also sure I turned everything back on. The water is running normally.

I have gas and a standard immersion. The gas or electricity can normally heat the water but now neither do anything. The heating does work as the radiators are working well.

I must have caused a air lock but I have no idea where to start. Their is a small pump under the gas boiler which explains very briefly to twist to remove air lock but nothing much happens and since the radiators are working I guess this is not the issue.

Can someone please advise? Please help as the children as getting smelly :rolleyes:

ART6

KevinC wrote: »

Hi,
The hot water has stopped working. I am pretty sure happened after I drained the system to fix a dripping tap. I am also sure I turned everything back on. The water is running normally.

I have gas and a standard immersion. The gas or electricity can normally heat the water but now neither do anything. The heating does work as the radiators are working well.

I must have caused a air lock but I have no idea where to start. Their is a small pump under the gas boiler which explains very briefly to twist to remove air lock but nothing much happens and since the radiators are working I guess this is not the issue.

Can someone please advise? Please help as the children as getting smelly :rolleyes:

The boiler will heat water in the cylinder through a coil inside it, while the immerser is inserted directly into the cylinder and is not connected to the coil, so the two problems are not related. Also, the hot water coil in the cylinder is not normally part of the same circuit as the radiators, so while you may have a flow through them, it doesn't follow that there must be a flow through the coil. That leads to two possibilities: When you drained the system, did you turn off the immerser? If not, it could now be damaged by overheating or sudden chilling when you reintroduced the cold water supply. Next, is your system atmospheric or pressurised? If the former then the coil should be venting to the attic tank, so an airlock is fairly unlikely. If the latter, there should be a vent valve somewhere on the coil circuit, and it could be stuck shut. If it's a pressurised system then you need to check that the system pressure is correct, and refill it if it is not.

The problem with the diagnosis is why should draining the hot water cylinder have any effect on the heating circuit from the boiler? I assume you didn't drain the boiler to repair a tap? In that case I'd suspect that you closed off a valve somewhere on the boiler to coil circuit -- on some systems there is a valve with a red handwheel on the inlet and outlet to the coil, and often a bypass valve between them. The bypass valve should be closed and the other two open.

The fact that you have a normal flow, but cold, through the hot taps is irrelevant since the water is heated indirectly by the closed circuit of the boiler and coil. The domestic hot water doesn't go through the boiler.

Anyway, aren't cold showers supposed to be healthy?:D

KevinC

>When you drained the system, did you turn off the immerser?
The electrical aspect was off and it has not been used since the summer as we used the gas to heat the water for baths.

>Next, is your system atmospheric or pressurised?
I don't know. The house is old built in the 60's but the heating & plumbing are recent. It is a bit higglety pigglety which makes following pipes hard. Their is a red cylinder beside the gas boiler in the attic area (dormer bungalow). I think this means pressurised?

I think the latter is more likely since the immerser was off for ages. (until I tried it for 15 mins). I'll have a poke around at the tap I may have messed with. I'll let you know how I get on.

Thanks for the advice so far.

KevinC

I managed to get it working! It was a handwheel which I must have forgotten about when trying to switch the water off the first time. I'll be more careful in future.

I guess it is likely that the electric immersion heating is gone but that some I'll worry about next summer.

Thanks a mill for your help. I think I draw a diagram of the system the next time I go tinkering.

ART6

KevinC wrote: »

>

Their is a red cylinder beside the gas boiler in the attic area (dormer bungalow). I think this means pressurised?

Yup. That will be the diaphragm cylinder that maintains the system pressure.

I think the latter is more likely since the immerser was off for ages. (until I tried it for 15 mins). I'll have a poke around at the tap I may have messed with. I'll let you know how I get on.

It would normally take a lot longer than 15 mins for the immerser to heat the whole tank from cold, so it might not be faulty at all.

Thanks for the advice so far.

KevinC wrote: »

I managed to get it working! It was a handwheel which I must have forgotten about when trying to switch the water off the first time. I'll be more careful in future.

I guess it is likely that the electric immersion heating is gone but that some I'll worry about next summer.

Thanks a mill for your help. I think I draw a diagram of the system the next time I go tinkering.

Glad to hear you're sorted.:)