Stopping water getting into a central heating pumps electrics

[pcolbeck]

My central heating boiler is bu**erd; I know this. It drips water from all sorts of joints and the piping is covered in limescale. It was a bad buy 8 years ago. It''s a combi oil boiler. Now we currently have plans being drawn up for an extension at which point I want to completely redo the heating to use a wood burner, oil, solar combination so I just have to nurse the horrid thing through another 6 months.
Yesterday it blew the fuse on the electrics going into it repeatedly so I opened it up and had a look. It seems water is dripping down the electrical flex into the electrics off the new pump we had fitted about a month ago and then poof !
What I need is a good way to seal the pump so that water doesn't get in. Currently I have the electrical part of the pump opened to dry out (and have sprayed it liberally with WD40) and have filled the nipple where the cable goes into it full of Castrol grease to see if that helps but does anyone have any better ideas ?

[rafletcher]

Well you could get a suitable IP65 gland to seal around the cable, but basically silicone bathroom sealant will do a good enough temporary job.

[tonycollinet]

Plus put a drip loop into the cable (cable goes down below the pump, and then back up into the electrical box) to prevent water dripping down the cable getting directly to the electrical inlet.

[Zoidburg]

And then wrap it in Denso tape

[mrcharly-YHT]

Please try to clean out every trace of WD40, and I suggest  you remove all the grease as well.

Central heating pumps get very hot. Combine this with oil/grease vapour + a spark and you have a recipe for trouble.

Silicone sealant is the way to go.

[pcolbeck]

The cables not long enough to put a proper drip loop in it unfortunately. I have made a  small loop that hopefully will make it drip to one side of the pump. I will try the bathroom sealant trick as well.   

[Ian H]

The cables not long enough to put a proper drip loop in it unfortunately. I have made a  small loop that hopefully will make it drip to one side of the pump. I will try the bathroom sealant trick as well.   

Improvise by binding enough tape around to create a point where the water will drip. You could extend it with tape or whatever so the water runs down it to a collection point.

[pcolbeck]

Ah well the pump she is shot. Taken to bits, dried out and set-up by itself with its electrics exposed as soon as 240v is applied there is a big blue spark and the fuse on the  lead supplying power to it blows. Bit annoying when its only about four weeks old. My friends is an electrical who works on this kind of thing in factories and he reckons water has got to the windings and done for them. The most annoying thing is that I did say to the guy who fitted it that I was worried about water dripping down the electric cable and getting into it but he assured me the seals would stop it. So now to B&Q for a new pump and some heat resistant cable so I can put a nice drip loop in it.

 

[pcolbeck]

Deep joy. The old beast lives and we now have hot water again. I can have a shower for the first time since Thursday !

[valkyrie]

Please try to clean out every trace of WD40, and I suggest  you remove all the grease as well.

Central heating pumps get very hot. Combine this with oil/grease vapour + a spark and you have a recipe for trouble.

Silicone sealant is the way to go.

Wouldn't worry too much about this. Central heat pumps get hot to touch, meaning between 60 and 100C, but auto ignition of oil will be at least 300C and the boiling point of grease that you'd need to create a flammable atmosphere - dunno, but very, very hot.

I've never come across an application that required flammable atmosphere zoning because of the presence of a lubricant.

[mrcharly-YHT]

I wasn't suggesting that the pump would be hot enough to set the grease/WD40 on fire, just that it would heat it up enough to create vapour - then sparking from the pump could ignite the vapour.

[pcolbeck]

Its a moot point now anyway as I got a replacement pump and mounted it the correct way up so the that the cable entered from the bottom not the top and used a new longer bit of cable that has a nice big drop loop in it. As it happens I had to take quite a bit of the piping out around the pump as the lime scale had seized up the fittings and I couldn't undo them. Got them all undone in a vice with some big stilsons and cleaned up with a wire brush. Carefully reassembled using PTFE tape on all the joints and tightened up well. Guess what that section no longer leaks at all. If I can do it then wtf couldn't the "proffesional" plumber who I paid to overhaul the thing a year ago get it to to stop leaking. Of all the tradesman I have run into plumbers are the only ones who don't seem to have any pride in their work and are simply interested in a fast buck.

[mrcharly-YHT]

Its a moot point now anyway as I got a replacement pump and mounted it the correct way up so the that the cable entered from the bottom not the top and used a new longer bit of cable that has a nice big drop loop in it. As it happens I had to take quite a bit of the piping out around the pump as the lime scale had seized up the fittings and I couldn't undo them. Got them all undone in a vice with some big stilsons and cleaned up with a wire brush. Carefully reassembled using PTFE tape on all the joints and tightened up well. Guess what that section no longer leaks at all. If I can do it then wtf couldn't the "proffesional" plumber who I paid to overhaul the thing a year ago get it to to stop leaking. Of all the tradesman I have run into plumbers are the only ones who don't seem to have any pride in their work and are simply interested in a fast buck.

Yes and no.

ptfe isn't recommended on CH joints because of it's potential to bugger up valves and pumps.

However, there are alternatives, such as fitting the ptfe carefully!

I became very disillusioned with paying plumbers when I had a major house extension done. Sent them away and finished everything myself. Problems solved.