Complete useless noob here when it comes to these things, but I had noticed a leaking pipe on the top of our hot water cylinder (in the airing cupboard) to which I have temporarily fixed my means of fitting a rubber washer (the nylon one appears to had failed) - but I am not sure how to fix permanent, hence the post.
Bit of background, we have a old Baxi boiler in the kitchen, pump, three way valve and HW cylinder in the airing cupboard and an thermostat on the landing and one on the HW cylinder. We have two tanks in the loft, a large cold water one (which assuming feeds the HW cylinder) and a small one, which I think is the HW expansion tank - both have vent pipes over the top and point back down into them - I think its an Open Vented system?
Now, I am not sure what the two pipes are that go into the top of the HW cylinder, one of them comes from the pump (so I assume its the cylinder coil feed from the boiler? and the other disappears under the floor in the cupboard (the return?) I can identify the cold water feed pipe and the hot water out pipe.
Both of these (15mm copper) pipes have a venting screw on the top which has flat threads (i.e. only has threads on opposing sides). They basically look like a copper T piece where one side goes into the HW cylinder and the other has a thread in it with the bleed screw.
One of these was weeping from the washer, I have replaced the faulty nylon washer with a rubber one and its fine now, but presumably need to replace with another nylon washer?
Also, in trying to stop the water from escaping when undoing the bleed screw I simply couldn't. I turned off the main cold water feed, and switched power off to the pump et al, and drained all the hot water taps till no water came out, but water still escaped out of this pipe - what water is this?
We had an issue where we had a massive air lock in the system, we had a plumber out who tried to vent the pump, then tried both of these pipes and found that the faulty one (wasn't then) released masses of air, which then made the system work again, but air has entered again, which is why I looked at it. He also identified that the HW expansion tank was too low, its about 1m above the pump in the loft, and also said the vent pipe didn't go high enough before it bends back down - it goes up about 40cm - and this needed extending.
I suppose my questions are:
a) Any idea what these two pipes are entering the top of the HW cylinder
b) Would what the plumber said about low vent pipe make air enter the system?
If any more info is required (and I fully expect there is) then i will try my best to supply it.
Thanks in advance.
Dan
Bit of background, we have a old Baxi boiler in the kitchen, pump, three way valve and HW cylinder in the airing cupboard and an thermostat on the landing and one on the HW cylinder. We have two tanks in the loft, a large cold water one (which assuming feeds the HW cylinder) and a small one, which I think is the HW expansion tank - both have vent pipes over the top and point back down into them - I think its an Open Vented system?
Now, I am not sure what the two pipes are that go into the top of the HW cylinder, one of them comes from the pump (so I assume its the cylinder coil feed from the boiler? and the other disappears under the floor in the cupboard (the return?) I can identify the cold water feed pipe and the hot water out pipe.
Both of these (15mm copper) pipes have a venting screw on the top which has flat threads (i.e. only has threads on opposing sides). They basically look like a copper T piece where one side goes into the HW cylinder and the other has a thread in it with the bleed screw.
One of these was weeping from the washer, I have replaced the faulty nylon washer with a rubber one and its fine now, but presumably need to replace with another nylon washer?
Also, in trying to stop the water from escaping when undoing the bleed screw I simply couldn't. I turned off the main cold water feed, and switched power off to the pump et al, and drained all the hot water taps till no water came out, but water still escaped out of this pipe - what water is this?
We had an issue where we had a massive air lock in the system, we had a plumber out who tried to vent the pump, then tried both of these pipes and found that the faulty one (wasn't then) released masses of air, which then made the system work again, but air has entered again, which is why I looked at it. He also identified that the HW expansion tank was too low, its about 1m above the pump in the loft, and also said the vent pipe didn't go high enough before it bends back down - it goes up about 40cm - and this needed extending.
I suppose my questions are:
a) Any idea what these two pipes are entering the top of the HW cylinder
b) Would what the plumber said about low vent pipe make air enter the system?
If any more info is required (and I fully expect there is) then i will try my best to supply it.
Thanks in advance.
Dan
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