Bath Problem - Airlock Every Time

[Eve]

When I run a bath it always seems to airlock the system.

I can get the airlock cleared though the next time I use the shower it seems like the hot water overrides the cold so the shower (over bath one from the taps) is scalding hot or dribbling cold. It then seems to fix itself.

Is there any easy way to fix this? I shower at least every morning but it's putting me off having baths due to the faff afterwards and I want to have more in the evrnings to help arthritis wise (nice radox soak :)).

[The Builder]

Do you have a gravity system Evie? (Immersion cylinder and a roof tank)
Or is it a combi boiler?

[Eve]

Ermmmmmm....I have a big green tank in a cupboard in my bedroom and there is another tank in the loft - it was leaking a while back as apparently set to emergency fill level (or something like that) so the neighbour said he sorted that and it stopped leaking (after the bathroom ceiling fell through).

When I'm in the bathroom trying to clear the airlock I can hear it bubbling up the pipes into the tank overhead as it's right above the bathroom.

[The Builder]

Yes, I remember your ceiling coming down :o(

The most common cause of this is that the roof tank is too small. The hot bath tap is fed from this tank via the immersion cylinder (big green thing).
I guess your cold bath tap is as well.

Simply, while running a bath, the roof tank empties down to a level below the outlets........... so it starts sucking in air instead.

If that's what's happening, then the only remedy is to fit a bigger roof tank, or, if one won't fit up there, then add another tank to increase the overall capacity.

Would it be easy enough to stick your head in the roof and tell me the approx dimensions of the tank?

[Eve]

Fraid not :( Never been up there, my neighbour had to swing himself up through the roof entry via the bannister until he brought a step ladder over when he was fixing up (my landlord paid him).

I've only seen a glimpse of it when the ceiling wasn't there, looks quite precariously balanced on some beams and was a little nervous sitting on the loo for a while as it was pretty much over my head...I was a little paranoid it would or tip or something.

Hmmm, seems like I will need to learn to live it it (or move), no chance of landlord changing it. The hot water runs out quite quickly too even though I have it on constant for hot water (I can never work out how to use the timer properly - it keeps switching on when I try to set it!).

I'm a lost cause (like the boiler) :)

[The Builder]

You're never a lost cause Eve :o)))

If it's so hard to get in there, then it's a good bet that the tank isn't very big.

The only thing I could suggest is to run the hot water into the bath first without the cold. The tank might just cope with that on its own............. then turn off the hot and top up with cold afterwards. That might give the tank time to catch up :o)))

[Eve]

Ahhh, I like your thinking :) I will give it a try, thank you.

[Hopkirk]

If it's an older house, the cold tap may also be fed from the cold tank in the loft. (I believe nowadays the bathroom cold taps are mains fed)

If so, perhaps run some cold into the bath some time before you want to use it. The roof tank can then fully refill before you start drawing hot water off.