Mira shower - and reduced pressure due to ... ?

[confused]

We've had a Mira Excel shower (probably about 8 years old - it was in the house when we bought it), and it's fed of a combi. The pressure has been excellent - until that is I took the plunge (sorry) and moved the hot and cold feed (in 15 mm pipes).

- I needed to move the pipes as they ran behind a false ceiling that I pulled down. - When I re-did the pipes I added 4 elbows to each run - so they could be tucked away between the floorboards etc. Now our pressure is rubbish.

Could adding 4 elbows in the hot and cold have such an effect? (There is almost a 6 inch S bend at one point) Or has some flux / solder got stuck somewhere in the mixer?

I'm trying to take the mixer off the wall at the moment to have a look at where the pipes come into it. - Though I can't work out how to get it off.

Any advice / help would be appreciated.

Cheers.

[Phil L]

You've probably created an airlock in the pipes

[confused]

Phil, good point, I'd not thought about that. I've done a search on this group on getting rid of an air lock. - Seems quite complicated. Anything I can do to narrow down where the air lock is? / Best way to remove it.

Thanks

[Graham]

Can you have an airlock that permanently reduces the flow? I would have thought that the flow would be cut off altogether.

Graham.

[Phil L]

Plumbing is not my forte although I have done bits and pieces here and there. The last time I came across an airlock, it was on a hot water pipe connected to a HW cylinder, I just connected a small length of hosepipe between the hot and cold taps and turned them both on, the cold water presure being higher forced the air trapped inside the hot pipe back to the cylinder and it never came back, whether this would work with a boiler I don't know.

That said, it's not clear whether the hot, cold or both have airlocks in them..when you turn the shower on, is it very hot, very cold or just normal, temperature-wise?

[Phil L]

It is reduced altogether..on one of the feeds, either hot or cold, the other should be OK

[confused]

It is a bit colder than it used to be, so I guess that leads to the hot water pipes.

Does it matter which two taps I connect? I have a mixer in the kitcken and then upstairs we have two sinks each with a hot and cold tap.

Thanks.

[Phil L]

I thought it might be, airlocks in cold pipes are a rarity due to the pressure.

You need to get water, hot or cold, into the hot pipe where you have adjusted it, as it is it is filled with air and no hot water can get past, backflushing itwith cold water is the easiest method, but without knowing the plumbing layout of the entire house, I can't tell you which taps to connect.....is the upstairs hot tap after the airlock too? - if it is before the airlock and you are getting good presure then it won't clear it, if it is near the shower suffering low pressure then it should clear ok, you need two people and a hose with two tight fitting tap connectors on it, turn the hot tap on first, only one or two turns, just to open the seal, then turn on the cold tap, the mains pressure should completely fill the hot pipes, flushing out the airlock.

[confused]

Excellent, yes the sink near the shower also suffers from poor hot water pressure. I shall try that at the weekend.

Thanks for the advice Phil.

Damien