How to Replace Hot Water System on Winnebago

Today we are going to be working on this Winnebago. It has an old hot water system that needs to be replaced.

We’ve ripped out the old hot water system out of the Winnebago. It used to be sitting in this hole here. Here’s the gas side of it. The first thing we got to do on it when we touch any gas on the van is to test the gas to make sure it’s not leaking. Because we can’t hook onto something, even if it’s the smallest leak. We can’t just say, “Oh look, it’s only a small leak. Someone else has done it and we’ll just carry on.” It falls on us then.

We disconnected the hot water system, turned off the tap, put it on test, and it just had this little leak somewhere. So we were looking around for it and it ended up being inside the cupboard. They used to have a gas fridge and that had a ball valve on it. But the gas fridge has been disconnected and a 12 volt fridge has been installed, which is amazing.

Leaking Ball Valve

But this ball valve, which was in the cupboard, was going to the stove and they’ve just cut it, folded it over once, and that was it. No welding or anything. So with the valve on like that, gas would leak out of it slightly. Look at the front of the cupboards, all the pots and pan rolling around. You could easily bump that and then that LPG would just be pouring out of that little fold over a bit. They really should have capped it off or got rid of it completely. So that took a bit of time to find this and to cut it out. We ended up having to put the Winnebago up on ramps like this on both sides. Because we couldn’t get underneath it. Chest is too big. So anyway, what we ended up doing is cutting that line off, sealing it off properly, soldering it so it’s not going to leak again. Test it all again, and now it’s all fine. And so now we can continue on just with the gas side of things.

Water Side

The water pipe is Quest. We’ve got to try to figure out a way to get this pipe to hook into the new hot water system. Here’s the old one that was installed there. It was very manual, similar to the ones you’ve got at home with the sit valve. So it’s seen its day. All the connections are on the back of it. So nice and easy to connect onto it.

But now the new one here, all the connections are at the front. We assume they’ve all got to come through here and then out this little hole to get into the van somehow. So that’s going to be quite difficult. The owner bought it and the guy in the shop who he bought it from said, “You’ll need these fittings and then he should be able to hook it up, no worries at all.” So he’s given me this bag of fittings, a couple of bits of blue and red pipe, which is helpful. We bought it by the roll anyway, but that’s not going to work.

Temp Valve

We’ve also spoken to the owner about putting a temp valve in just to make it safer and you use less water then as well. Check out our video on the temp valves in our Forbes 15+ caravan. Awesome for saving waters and super safe for kids.

This is where that little pipe was that was leaking. It’s just inside that cupboard there. So you got boxes inside there that could have moved around and turned that little valve on. There’s your little 12 volt fridge. And here’s where the hot water system’s got to go. These are the pipes with the fittings. We don’t even know if you can get these fittings anymore.

This is the cold line going from the pump and head off down here and that’ll go underneath. And this is the hot main. So we’ve got to get a temp valve set up in here. That’ll beset for 50 degrees. And so we need a hot main coming off the hot water system straight into the temp valve. And then also cut some tees to get the cold going with an isolation valve.


There’s a fair bit of mucking around with the water side of things. And also the old hot water system didn’t have any electronic stuff. There wasn’t a switch. Nowadays you can just switch them on and they’ll light up themselves. It didn’t have any of that stuff. It just comes with a few wires. They come out the side of the heater and then they’ve got a couple of switches. So that needs to be hooked onto the 12 volt. Hopefully Glen next door can help us with that while it’s here if he’s not too busy making his air horns.

We’ve just done the temp valve and adjusted the water, but just come and look at this. This is the setup here that we’ve got at the moment. It’s a lot easier to do on the bench of course, so it’s great when you’ve got a workshop. This is the gas line. We’ve tucked that through the hole there, and then we’ve got the cold main going down there. Now it’s very important to put little sleeves in there so the water doesn’t pop off. And this is the hot main.


Now this sort of pipe here, it’s still a John Guest pipe in there, but it’s built to the Australian standards so you can have really hot water out of it. There’s very limited chance that that can pop off because the normal blue stuff that you use only has one wall. These hot water systems go up to 60 degrees, even 70 for some of them, which is great for storing heaps of hot water. But when 70 degrees comes in contact with the blue or the red pipe, it just softens that little bit and sometimes it can pop off. So you don’t want that inside your caravan.

The white pipe’s especially made for that. The walls are a lot thicker and inside you can see there’s a little line of aluminium in there. So it locks it in nice and tight. It can’t really expand or pop off or anything like that. It also has a little sleeve to go inside it. They’re a lot thicker and in a different size. So the water can’t come out. So if you’ve got a storage hot water system, ask your plumber, make sure that they use the approved ones. The ones that look like this John Guest fitting set, with WaterMark approved. Really nice stuff.

So the 70 degree water will come out and go around and then it’ll go into the side of the temp valve. Cold line will come on the other side and then the 50 degree water will come out the bottom.

Water Done

We’ve cut out the old pipe here, the old Quest. We’ve done some adapters and changed it over here. This is the pump where you fill it up or not fill it up. So you hook it to the mains and comes through here. We’ve changed over. We’ve got a T here that goes round here onto the isolation valve for the water supply of the hot water system. And then it goes across here and this is to the cold side of the temp valve. Now that white pipe will come into here. That’ll be the super hot pipe. So it’ll go straight into the hot side. And then there’s tempered water. We’ve got a fitting here that’s locked on so it’s nice and solid. And that goes down to the existing hot main.And there’s a little T there. That’s got to go down into the hot water system. So the cold water will come in here, go down and through there.

What we’ll do now is get everything set up, put a sealer on there, get it in position. Then I can hook up the gas and the water, and then we can see about getting Glen next door to hook up the pump.

Pump Issue

We’ve hooked up the water and tested the gas, so that’s all good. We got all the pipes going through. So this is a 70 degree water, whatever that can go on that John Guest white pipe. So everything all goes through this little hole. We’ve got to seal that up once it’s all done. Here’s a pressure relief valve to go down here to leak out of there. The problem that we got is that when we’re running the pump, it just takes a long time to turn off. It should take three seconds or something to turn off. So the pump’s just down in there. It’s quite an old one. And you watch here when we turn the water on. It’s just a bit spluttery. See how it’s spluttering around? And then when you turn it off, that pump you can just hear, just keeps going and going and going. They’re still pumping away.

So what we think is the issue is that, see it’s got this retic filter on here that goes all the way down. So we got 9 joints on that pipe. If one of these is leaking and letting air through, it’ll cause issue with the pump not turning off because there’s a bit of an airlock in there. So we told the owner, “Look, this pump’s quite old too. Do you want to just put a new pump in and then also just get rid of this?” They’ve got these really nice little clear plastic filters that fit especially for these pumps to clean it, get rid of this thing. That’s mainly just for the retic.


And then also when you hook onto the pressure from the mains at the caravan park, this all builds up pressure. And then that pressure can go back into the pump here. So there really should be a check valve in between here and the mains where the mains goes on so that pressure can’t come back to the pump anymore. That’s probably the best thing you can do. Cut that whole section out there. Fix up, put a check valve in, put a new pump in. Just shift it down a little bit, give it a little bit more room. Ahole new suction line onto the tank below. And then we reckon that would sort the problem out.

New Pump

Hot water system’s all replaced and everything but these old Winnebagos, motorhomes, and caravans all in general, there’s always something else that crops up as you’re working through it. But anyway, that splattering has stopped. Here’s the old pump here. So this is the line here that was going down through there all the way and that was going onto the bottom of the tank.

See all these 9 joints are just pushed on with those rubber plastic retic ones. So they’re not really that great. It’s just for the drip feeds. So air could have been sucking in from any of these things as well. And this is a filter too. See a little mark there, that probably could have been a line that was loose. So that’s why it was spluttering all the time. And here’s all the gray fitting. So this one came from the town water through there.

Check Valve

And as we pointed out before, there’s no check valve. So when it was connected into the mains from the caravan park, you’d have that back pressure pushing on that diaphragm all the time. We don’t know how old this pump is, but we spoke to the owner and then it’s just a case of, “Look, what do you want to do? We’ve got to replace this suction line for another $150. Do you want to put a new pump in while we’re there?” We’ve still got to remove the old pump anyway to get it all off. Is it worth it? Because it only takes another 15 minutes to whack a new pump on there. So he said, “Yeah, go ahead with that.” And then we can just get rid of all this gray pipe as well.

Set Up

We were able to tuck the pump just down this way a bit more so it’s a bit more out of the way. So here’s the suction line. It’s just got one joint going down that goes underneath, sealed it up with the silicon so the stuff doesn’t come in there. And this is the little inline filter. They’re great. You can see when they’re dirty, easy to clean off. You just take them out, clean out the stainless steel filter, and that goes into the pump. So when the pump’s working now, it comes out of here. This is the inline check valve. So water can only go this way. So when you do hook it into the city water out there, that’s a pressure limiting valve and a check valve. When it’s pushed into there, the water will come in here but it can’t go up and damage the diaphragm into the pump.

And then you can see here the water goes up to a T, that goes around to the hot water system. That’s to shut the hot main and the cold water off to the hot water system and then it goes up into the cold side of the temp valve. And then we got the really hot water coming into that white pipe we talked about before. And then this one goes off to the kitchen sink and everything like that.

Electrics Sorted

So Glen next door has put the switch in for the hot water system. He’s just about switching that on. She lights up as long as the gas is onto it. The gas valve is down there. As long as the gas is valve, she’s fired up. So the water’s nice and hot now. We show you how it doesn’t splutter anymore. So it’s definitely had some issues there. Really good flow now and see how quiet it is. You can hardly hear it.

We really like the Shurflo pumps. They’re great. The smaller ones seem to really just be really loud. So if you do use the water at night and stuff, it could wake your wife up or your partner. And the hot water too, that’s working great. So takes a little bit but then it gets hot, super hot. Now the water’s really hot in the tank but it only comes out at 50 degrees so that’s still too hot to put your hand under and then you got the shower and everything in the basin in here like that. And the pump’s turning off a lot quicker than it should do now. It wasn’t just kept running and running anymore. So yeah, it’s a great result. He’ll be happy with that.

All Done

We like leaving all the old gears. This is that gas valve that was going to the fridge that they just bent it over and smashed it up a bit and then said, “That’ll be all right.” But if that valve is ever turned on, that’s when i’td be leaking. And LPG is shocking because it’s heavy than air. It sinks down and that’s when it could explode. Some videos online in JB’s or one of the bigger caravans, one of the stoves had a gas connection. It broke in the aluminium connector or something and then filled up the cupboards and you see the walls are lifted and everything.

But anyway, we always like leaving all the parts in the box so people can see what’s been replaced. So we will leave it there for him to sort out. So all good, another successful build. Happy to get this one out on the road. If you need to replace your storage hot water system and you live in Perth or you’re coming over to Perth, yeah, give us a call. We’ll be happy to help.