Posted by in Plumber Talk, on September 5, 2017




This video will give you the basic system information needed to understand a vented hot water system. How they work, what the plumbing connections are and where to buy them online

Please subscribe and favourite!, honest reviews and advice. Holla, and welcome to today’s video. Today, we’re gonna have a look at domestic heating pumps, how you change them, how they work, the things that can go wrong with them, and just everything about them. If we miss anything, let us know as usual and we’ll get back to you. Here is a central heating pump.
Now, this one is inside a combi boiler, but you can also find them in your airing cupboard or anywhere, really, on the heating circuit that requires flow. They’re generally in the airing cupboard or in the top of your combi boiler. Now, if we look at this one, firstly, you’ll notice that the shaft is actually pointing up in the air. Now, this has been installed incorrectly. If air can get up in the shaft, this would actually seize, so that’s what’s happened with this pump here. It’s actually seized up and it’s not working properly. So, we’ve got a new pump to put in here, so we’re gonna shut these gate valves off here, whip the pump out, do the electrics, pop the pump back in, turn the gate valves on, vent the pump, have it the right way round, and hopefully everything will work fine. One thing to remember is, while it’s not a good idea to have the shaft actually pointing upwards, you can have it pointing horizontally, or any way that air will not get caught in the shaft part in the electronics bit of the actual pump itself. So, never have the pump upwards. Don’t do it, it’s bonkers. So, firstly, isolate the electrics and turn off the heating system, everything, make sure it’s fully isolated. If you’re not competent in doing anything electrics, or anything like that, don’t do it. Once you’ve done that, turn each one of the gate valves off. Once you’ve turned the gate valves off, get a fat screwdriver, undo this, and vent any pressure or water there might be. We do this because then we know that the gate valves are holding. Now, if water still comes out at this point and just keeps on coming out, the gate valves aren’t holding and you’re gonna have to drain the whole system down, which is a complete annoyance. If you don’t know how to drain a pressurised system down, look at our channel, and it’s the same for a feed and expansion system. Just go back to the channel and you’ll find it all there. If we look closely at the inside of this shaft, we’ll see that there’s a small slotted screw bit at the end. Now, if sometimes, the pump can get seized and you can pop a little slotted screwdriver in the end of that, and spin it, and that’ll un-seize the pump, and you never know, you might not need to change it anyway. So, we’ll have a quick look at there and you can see what I mean. So, if we look in here, there’s our slot, our small slot just there, pop our screwdriver in there, and that should move. Now that’s moving alright, but this one’s actually got a burnt out windings. Before you remove a pump, always make a note of the direction of the pump. You’ll find that somewhere on the body, there’ll be a little arrow pointing in the direction that actually pumps the water. Make a note of that and when you put the new pump on, make sure the arrow on that new pump points the same way. Right, so now we get a big set of grips. Now, these can be hard to undo. Oh, these are lovely and loose. Look at that. Beautiful. And that comes off nice and easy. Do that to each end, and there we go. Old pump out of the way. So, it’s a good time once you’ve got the pump out, to check inside each one of these valves, to make sure they’re not all clogged up, ’cause they do get clogged up. The reason for that is there is a magnetic force around the pump, and you have very small particles of metal going round through the water, and they get attracted to this area, and they basically clog it up in the end. So, its always a good idea just to check in there and see how clogged up it is. Let’s have a wee little peek at our new pump. Pumps are all generally the same length, so you should find that it’ll fit in the old slot okay, so that’s great. And also, make sure you don’t lose the fibre washers or the rubber washers. Now, these rubber ones are always a lot better. Fibre ones are just slightly harder to make a seal. They create a seal on the flat here to the flat on the actual pump itself. I’d also recommend as well, when you’re working on these, it doesn’t hurt to get a little file and just file these off so they’re nice and clean.

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