Leak at circulation pump

necstandards

I replaced the circulation pump last year but I could not seal the joint between the valve and the pump. Yesterday I replaced the bottom valve again (as indicated with the arrow in the attached photo) in hope to stop this leak.
I remove the pipe spool from the below and valve compression fitting and completed the replacement at my bench vice. So removed the old valve and gasket. Wire brushed the valve face and threads and gave a light sanding to remove any old gasket. Replaced with new valve and new gasket (those green fiber type) and tightened well as I had it in the vice I thought I got a very good squeeze. Then fitted it all back up. To my horror its still leaking. Can anyone offer advice for what I maybe doing wrong. This leak is driving me nuts. Thanks for reading.

listermint

Had the same issues with mine, the leak was tiny and stopped after a few days. Maybe sit tight and monitor it for chance give it a day or so.

sky6

Was the Washer in place when you put the Pump Valve back together.? You could have over tightened it tearing the Fiber seal in the process.

You could also use ptfe tape on the threads or a thread sealer. Something like Plumbers mate should seal it.

rightjob!

Use the rubber pump gaskets instead ,also id get that safety valve piped to a suitable loction!

agusta

rightjob! wrote: »

Use the rubber pump gaskets instead ,also id get that safety valve piped to a suitable loction!

+ 1 and dont over tighten

K.Flyer

sky6 wrote: »

Was the Washer in place when you put the Pump Valve back together.? You could have over tightened it tearing the Fiber seal in the process.

You could also use ptfe tape on the threads or a thread sealer. Something like Plumbers mate should seal it.

PTFE on threads will not stop a leak on pump valves, nor do you use plumbers mate.

@o.p.
Go into your local suppliers and get a pair of rubber sealing washers for a circulation pump and that will be the end of it.
While you are in the suppliers, do yourself a favour and get a pair of Gate Valve type Pump Valves and that will really be the end of your woes. Those valves that you have are cack, I stopped using them years ago.

Tom44

316
Elbow above pump valve leaking too, as metal expands and contract with heat.
+ NEVER use Safety valve for draining, you'll end up with it leaking too.
Or, what's the fitting in it for?

necstandards

Tom44 wrote: »

316
Elbow above pump valve leaking too, as metal expands and contract with heat.
+ NEVER use Safety valve for draining, you'll end up with it leaking too.
Or, what's the fitting in it for?

I think thats the relief valve ( i can twist the top and it seems to open) - i used it to bleed some of the air out when refilling.. maybe thats totally wrong (boiling water does spout out and not the smartest thing to be doing really)

Thanks for all the replies - will get the rubber gaskets and try again

freddyuk

Wire brushing the the valve seat would have left scratches in the soft brass surfaces. This was not a good idea. It may never seal with a gasket.

necstandards

freddyuk wrote: »

Wire brushing the the valve seat would have left scratches in the soft brass surfaces. This was not a good idea. It may never seal with a gasket.

Thanks - i incorrectly stated it was the valve i wire brushed - in fact it was just the pump sealing face.

freddyuk

A lot of installers use PTFE on compression joints which may help on second hand joints and this is where the tape is - not on the pump valves?
It is a sign there is little confidence in the ability of the installer in my view. The odd joint to facilitate removal of certain service items may help. In any event properly soldered end feed joints are the only neat and by far the cheapest way of doing the job. Endless compression fittings cost a fortune and look ugly and they are impossible to insulate correctly....