Hi all - first post from me but long time lurker - any advice gratefully received...
After draining my water tanks and pipes in order to move appliances round a new kitchen, my gas boiler no longer heats my water cylinder. Cold water flows steadily from my hot taps. Gas central heating works as it should.
I read that this is a common problem caused by an airlock after draining, and so followed the advice to clear this - connecting a hose from the cold mains appliance outlet to the neighbouring hot appliance outlet and running mains back up into the hot pipes. I was alone the first time I did this so I wasn't able to watch for any bubbles in the cold water tank in the loft at the time. When repeating this with a helper, up in the loft I can see this causes the level in the cold tank to rise (any bubbles will have long since cleared). So I don't think I have an airlock between the hot water cylinder and the cold tank in the loft.
Furthermore the hot cylinder seems full, because the immersion heater works fine. After using the immersion heater hot water comes steadily out of all the correct taps. So I don't think I have a problem between cylinder and taps either.
If I hadn't just drained the system, I would have guessed the problem was either with the three way valve (or the controls). The pipe going to the three way obviously gets hot as is what I assume is the pipe going to the radiators, while the pipe going from the three way to the cylinder is cool. But, I feel crazy talking about the motorised valve when I know that the system was just drained and the problem occurred immediately afterwards and ever since. Yet I have done what is advised to clear an airlock and still no luck.
The only other thing that might be relevant is that originally I tried to isolate the cylinder (to avoid having to drain the whole system). I tried to turn a valve on some 15mm pipe going into the bottom of the cylinder using a spanner (valve wheel is missing) - but it was possibly jammed. I thought it was turning when I was closing but now it comes to opening it up again I see that I was probably just spinning the spanner around on the shaft. In any case, going into the bottom of the cylinder as it does this pipe must be the cold feed in from the loft(?) and the cylinder seems to be filling OK, so I guess this valve is open, and is not the problem.
Could it be some safety mechanism on the motorised valve preventing the cylinder being heated while drained, that I need to reset somehow? Or is there something else I need to do to locate and clear a remaining airlock?
Any advice gratefully received!
After draining my water tanks and pipes in order to move appliances round a new kitchen, my gas boiler no longer heats my water cylinder. Cold water flows steadily from my hot taps. Gas central heating works as it should.
I read that this is a common problem caused by an airlock after draining, and so followed the advice to clear this - connecting a hose from the cold mains appliance outlet to the neighbouring hot appliance outlet and running mains back up into the hot pipes. I was alone the first time I did this so I wasn't able to watch for any bubbles in the cold water tank in the loft at the time. When repeating this with a helper, up in the loft I can see this causes the level in the cold tank to rise (any bubbles will have long since cleared). So I don't think I have an airlock between the hot water cylinder and the cold tank in the loft.
Furthermore the hot cylinder seems full, because the immersion heater works fine. After using the immersion heater hot water comes steadily out of all the correct taps. So I don't think I have a problem between cylinder and taps either.
If I hadn't just drained the system, I would have guessed the problem was either with the three way valve (or the controls). The pipe going to the three way obviously gets hot as is what I assume is the pipe going to the radiators, while the pipe going from the three way to the cylinder is cool. But, I feel crazy talking about the motorised valve when I know that the system was just drained and the problem occurred immediately afterwards and ever since. Yet I have done what is advised to clear an airlock and still no luck.
The only other thing that might be relevant is that originally I tried to isolate the cylinder (to avoid having to drain the whole system). I tried to turn a valve on some 15mm pipe going into the bottom of the cylinder using a spanner (valve wheel is missing) - but it was possibly jammed. I thought it was turning when I was closing but now it comes to opening it up again I see that I was probably just spinning the spanner around on the shaft. In any case, going into the bottom of the cylinder as it does this pipe must be the cold feed in from the loft(?) and the cylinder seems to be filling OK, so I guess this valve is open, and is not the problem.
Could it be some safety mechanism on the motorised valve preventing the cylinder being heated while drained, that I need to reset somehow? Or is there something else I need to do to locate and clear a remaining airlock?
Any advice gratefully received!