air lock or blockage?

[TerryWaite]

went to a job today where problem was hot water was just trickling out of the taps. Hot water is from an indirect cylinder, Y-Plan, upstairs, tank in loft.

I opened hot kitchen tap, water comes out for 20 secs then dies. Upstairs hot taps the same, possibly even worse. All cold taps in the house are ok, they are mains cold water.

I am suspecting an air lock but is there anything else it could be? I tried to bridge between the hot and cold taps with some foam insulation and then blast it through but i couldnt get the full pressure through the lagging and this proved unsuccessful.

I went upstairs to check the storage tank, it was full, float valve working ok, i put my hand in down to the bottom to check for sludge, there was not much, and the outlet seemed completely clear, you could get your finger in and it felt clear.

I am going back tomorrow as it was getting late, I am going to connect the mains to the hot downstairs under the kitchen sink and try and blast it through properly, my question is, is there anything else at all it could be or is there a chance that this wont clear the air lock (if it is an air lock which i suspect it is)?

Another thing of note, there doesnt seem to be a cylinder thermostat fitted, the hot water coming out of the taps is absolutely steaming, would this cause any excess scale/blockages???

Any opinions mucho appreciado

thank you

John

 

[thomas donovan]

i tried to blow through a hose to get an airlock out many moons ago, 6 metres of pipe above me, nearly fainted and burst a blood vessel in my eye lol. bought a wet vac in the end:dunce2:

 

[billychuff]

i've had a couple of these and suggestions from others are bang on:
1) i had a load of insulation in the gatevalve from the tank
and on another job
2) Put a wet vac on one of the taps, sucking didn't work, put it onto blow and... hey presto

 

[glenno1]

If they have mixer tap just open hot side put hand over the spout and slowly open cold side,this usually clears it.If no mixer then its wet vac or hose from hot to cold tap

 

[TerryWaite]

personally my first point of call is straight to the cylinder cold feed for blockage in the base.
i rig up a hose and shove it down the cold feed via the tank with the hot bath tap fully open.
try that.

Thanks Redsaw I owe you a mars bar, I did just that and whoop dee doo it worked. Thank you

 

[ams3521]

If they have mixer tap just open hot side put hand over the spout and slowly open cold side,this usually clears it.If no mixer then its wet vac or hose from hot to cold tap

Thanks Glen, every now and again I get an air lock in my system and your hand over the tap method worked a treat, it's also saved me a lot of ear ache from the wife.