Water heating connect

[1 Cup]

Non return vales how to use and where to place @ cost £2 to £25. inline non return vales from tank to taps via pump, cold and hot water. 12mm pipe
So non return vales x how many 2, 3 ,4 or5. 2vales 1 on each tank ?
4 vales after pumps in each line ? 4 vales 4 after pumps .ie 2 hot 2 cold
Five vales used .3 on hot water 2 on cold water at taps.? 2 after pump one at tank.
I dont know where to put them for a better mixture ! Im useing house hold mix tapes ie 15mm mono mixer taps at sink and shower.
1 pump pressured system. Or 2 pumps and if 2 ? What best paces for them in line ? for hot water at 70 degrees. Make and modle please. Pics and link are better for me for hot water as have cold pump.
TIA

 

[SquirrellCook]

I normally only use two. One on the hot side of the water eberspacher to stop reverse flow when the engine is running. The other one is on the cold feed to the calorifier. The idea is to stop heat back feeding the cold supply.

 

[Squiffy]

Little bit confused here, unless I've missed the point. I use pumps with built in non return such as Shurflo trail king, unless you use a submersible rotary I don't see the point of using non return valves. I also use household mixer taps and have never had a problem with cold water feeding back to the tank or back to the hot water tank? Phil

P.s. The system pressure with the pump turned off also stays pressurised for weeks too, so I can return to the van after its been unused for a couple of weeks, open the tap and it still flows till the pressure in the system falls to nil.

 

[SquirrellCook]

The idea for the non-return valve on the cold feed to the hot water tank is to reduce heat being lost into the cold pipe. I'm sceptical about this, but also not sad enough to prove it. For the sake of a cheap valve I see no harm in it. Just remember you will also need an expansion vessel in the hot circuit.

 

[wildebus]

Out of possible interest, I got my expansion vessel from Screwfix along with the Heater - and then I found the same Expansion Vessel at HALF the price on Amazon. So sometimes the most unlikely sources can work out cheapest

(just had a look - it is 60p now than 2 years ago and the heater itself might be cheaper than Screwfix as well now?)

 

[1 Cup]

Right so expansion vessel and shuffro water pump on cold will make a non return ish and keep the system pressurised. Lovley. Thanks

Will all pumps take 80 , 90 degree water or are they different ?.
Just brought a 20 ltr tank new £10.00 from properjob .but how to get a 22mm nut on inside.

 

[Squiffy]

Right so expansion vessel and shuffro water pump on cold will make a non return ish and keep the system pressurised. Lovley. Thanks

Will all pumps take 80 , 90 degree water or are they different ?.
Just brought a 20 ltr tank new £10.00 from properjob .but how to get a 22mm nut on inside.

The pump should only pick up and deliver cold water to the cold taps and hot water tank. The hot water tank is under pressure from the pump, when the hot tap is opened hot water will flow from the top of the tank to the open hot tap, whilst the pump will replace the hot water with cold at which time the heater will start heating the water again, ready for when more hot water is required.
As for the 22mm nut, is there not a service access to reach inside or at least a cap that will allow a 22mm nut to enter the inside? Phil

 

[1 Cup]

No it opening is for fule nozzles. Got the 2 x 15mm barbed on with a longer stick taped to the ring spanner. So they are tight, but the bulkhead 12mm pipe fitting is a bugger.

 

[SquirrellCook]

What stops the water boiling in your heat exchanger?

 

[1 Cup]

Temp probe stops circulating pump. so nothing but a 120derees it will drain back to empty tank. I think that's how it works, I don't know ! ?.. my thinking was it runs empty . I'll call them
Thanks

 

[1 Cup]

So the black male 12mm to 15mm work as is . Lovely. Plastic to metal. The grey 12 mm plastic female leak like a sciv e at metal 15mm end, so put pdf tape on 15mm metal tap inputs and still leek under pressure when water pump is on!. The nut walls deformed when tightened on the grey plastic. 12mm fitting without heat .
Is there a better fitting for the female metal to plastic ? As I dont want a to put jubilee clips on 15 mm male end of mixer taps to hold grey plastic nut connection water tight.
Cant sleep as I wont stand water leaks
This is a 12mm push fit system and the sink has great water pressure with male connection.
Its the shower that both sides leak.

 

[SquirrellCook]

It would really help with pictures of the offending items.

 

[1 Cup]

Like this shower and stop vales don't like grey fittings. Kitchen sink put black ones on and no leaks.

 

[SquirrellCook]

I think this looks like one of those job where you need to be cool, calm and collected. Where you have a rigid pipe into a push fit socket, chamfer the pipe so it doesn't damage the O ring. If you rigid pipe is too soft there are inserts to put inside the pipe.
With the threaded fasteners, the thread should not be making the seal. So you shouldn't need PTFE tape. Just make sure each part has a compatible seat.
Sometimes if your crafty and you have incompatible seats you can use a fibre washer, O ring or even and olive to make the seal.

We're spoilt having a machine shop at hand, I just ask Anita to machine an adapter to make it work.

 

[1 Cup]

The 12mm red and blue pipe sills well it the other end, nut end, ,!.on grey. Are they bsf or 15 mm I dont know.
The pig tails are cheap mite just buy those and fit male.
Will try more pdf tape on female but they should work out of box the lazy f#ckers.

 

[1 Cup]

All good now just pulled rubber washers out of others. So put 2 rubber washers in one grey connection now. To shorten thread and ptf tape stopped leaks.

 

[1 Cup]

Only shower head to reduce in depth to get it has high as a possible in ceiling, for over head waterfull shower head.

 

[SquirrellCook]

All those non return valves would be asking for trouble in very cold weather.
Unless you pressurise the system with air it would almost impossible to clear the pipes from water.

BTW, I expect it's installed now.

Mark

 

[Squiffy]

Quite frankly I've never had the need for non return valves, all systems that I have installed have been with a pressurised system and out of five that have been installed never has water gone back to the tank the pump valves have been more than efficient as Mark says with all these no returns there is room for more problems and Emptying the system would be a nightmare. Phil

 

[trevskoda]

Truth is you dont require a hot tap in a van, better to have a big kettle to boil water using a gas ring, keep it simple.