Re: Pipe freezing sprays - any good?

Er, hot outlet, surely? If there are two ...

Or to be more specific, the outlet from the cold water storage tank (usually in the attic) which goes to the bottom of the hot water cylinder. On some installations there are two outlets of which one (which should be slightly lower) feeds cold taps in the bathroom and maybe WC cisterns, and the other (slightly higher) feeds the HW cylinder.

Be careful what you use. Once I thought a bung of bluetak would do the job. Damn' nearly got sucked down the pipework! If you don't have a Drayton-type bung the finger of a rubber glove with a silicone nozzle inside it works for 15mm outlets. Vacu-vin stoppers may do for 22mm.

There should be another route into the hot cylinder via the so called expansion pipe.

I have collapsed a cylinder whilst draining it. the air was supposed to go in via an auto bleed valve, but didn't.

A carrot can be pressed into service here if you are completely stuck...

Or, if you have only the can and no jacket, I've seen a teatowel and a couple of turns of gaffer tape work just as well!

-- Rob

Very true!

Quite a few people inc Numatic do these or have done in the past. Just a sub pump with a float valve & a bit of pipework.

It did occur to me that a submersible in a suitable container before the main vac (which wouldn't even need to be a wet'n'dry) would do the trick.

Just need to find suitable container.

The vac would need to be wet & dry. Dry vacs have direct air cooling to the motor, so moist air would fuber it. Wet vacs have by pass or secondary cooled motors so moist air is exhaused elsewhere.

Pump out vacs tend to have the pump in the bottom of the vac container so they tend to be larger sized machines.

Its surprising how much these vacs hold relative to the flow rate you get from CH and tank fed HW systems if some effort is made to restrict the flowrate. In my limited inexpert experience plenty of time to cut a pipe and get a isolator, TRV or blank end on. The nice thing I like about them is their ability to suck the water sideways as it comes out of the pipe - no need to get the nozzle underneath.

Well my apprentice and I did something pretty similar to change a stop valve on the mains the other week. We got everything ready had the full bore lever valve OPEN then simply chopped through the horizontal pipe with the pipe cutter I held the bucket and he put the valve on to the pipe, as soon as it was on I held the valve firmly in place, he turned the valve off and then tightened the compression nut. We also had a 15mm speedfit button to hand if all else failed and we were in a cellar.

I think thats the fun thing. Getting the water to follow the airflow - you can even make the water go around pipes!