Blocked pipe

The Waxbill

I've got a negative head pump in the hot press downstairs that supplies a shower and also the sink and toilets upstairs. The pump packed in a few days ago and when I removed the pump I discovered why. There was no water coming out of the feed pipe to the pump so it got starved of water.

The pump's cold water supply comes from a cold water storage tank upstairs in the crawl space. I presume there is a blockage in the pipe but I've tried putting a water hose on it to try and blow it out but no good, it seems to be a very hard blockage. Any ideas of how to unblock this without having to replace the pipe run from the cws tank to the pump?

Wearb

Have you tried a drain snake?

Are you able to see/feel the outlet from the tank?

The Continental Op

I think your going to have to get up in the roof and clean the tank. Can't imagine anything nice blocking the pipe.

The Waxbill

https://www.boards.ie/discussion/comment/120710196#Comment_120710196

I've been up there, drained the tank down, cleaned it, there was a lot of sludge at the bottom. Disconnected the pipe from the tank and managed to get a wire hanger in as far as I could without meeting a blockage. Did this from the pump side also with no joy. Unfortunately the blockage seems to be in a section that I can't get access to without tearing down ceiling or taking up a section of floor.

The Waxbill

https://www.boards.ie/discussion/comment/120710165#Comment_120710165

What is a drain snake? Would it go through 3/4" copper/qualplex pipe? There's a couple of 90 degree elbows it would have to pass through also.

Lenar3556

Why is there a negative head pump in what wouldn’t normally be a negative head situation? (Water storage tank is higher than pump)

Possibly the supply to the pump is airlocked or needs to be primed rather than blocked? Not typical scenarios but might explain the negative head pump.

Connecting mains pressure onto the bottom of the supply pipe to the pump should tell a lot. Put a valve on the end of the pump feed pipe first if there isn’t one there already.

Wearb

Look up drain snake

https://www.boards.ie/discussion/comment/120710373#Comment_120710373

A wet vacuum cleaner also worth a go.

The Continental Op

If nothing else is working I'd try sucking at one end with a wet and dry vac and then I'd put an air line on the other. Probably make up fittings so both could be attached to the pipe. I'd give some thought to how much pressure I'd apply with the air line but as our mains supply is up to 150 psi I don't think I'd worry up to that amount of air pressure being applied.