Understanding motorised valves

[AP77]

Hi,

I'm sure this is a probably ridiculous question, but here goes.

I have a Danfoss 3 port motorised valve.

I understand water enters the valve from the vertical pipe at the bottom of the motorised valve and goes to either the HW, CH or both depending on what has been selected from the control in the kitchen.

If both the HW and CH is selected, how does the water for the CH (which contains inhibitor) pass through the motorised valve at the same time water for the HW (i.e. that passes through to the hot taps)?

I don't understand why I don't get CH inhibitor coming out of hot water taps and why I don't get water without inhibitor (i.e from the hot water tank) into the central heating system.

Thanks!

 

[Echo the husky]

The systems water is completely separate from the water that comes out of your taps, see stolen diagram below:

 

[ianmcd]

the DHW goes through a coil inside your HW cylinder and transfers the heat that way, the two waters never meet

 

[Terrywookfit]

Stop lying to him................It's Magic !

 

[dilalio]

It’s done by a magic process called heat exchange

Edit: unless your cylinder coil is ruptured

 

[AP77]

Thanks for the replies.

Sorry, I still don't quite get how the motorised valve part works does, although clearly it does.

Looking in my airing cupboard, water appears to flow into the motorised valve through a single vertical pipe coming up through the airing cupboard floor, before going either to the HW, CH or both. Just before the motorised valve the pump is positioned. If HW and CH is selected, water flows up into the motorised valve and then splits and goes in both direction to HW and CH. The CH flow then goes out through the floor in the airing cupboard and the HW flow goes into the hot water cylinder, with a separate vented branch pipe.

I guess some of my understanding here is still not right because the same water supply (the pipe that goes through the motorised valve) can not be going to the hot water taps and central heating, can it?

....apologies, I am sure this is really obvious.....don't think I'll ever make it as a plumber!

 

[dilalio]

Think of your cylinder as just another radiator... hot system water travels through it in a coiled pipe and transfer heat to the water surrounding it (inside the cylindrical ‘tank’) just as a rad transfers that heat to the ‘air’ surrounding it (inside a room).
The mid position valve is merely a ‘switch’ that allows the cylinder-rad to be included or excluded from the route taken by heated water from the boiler and back.

 

[Echo the husky]

The boiler water goes into a coiled pipe inside the cylinder of fresh water being heated. See here:

There is a rather rough video complete with swearing showing the inside of one on youtube.

 

[AP77]

Thanks very much for taking the time to explain further, I get it now!

The missing link for me was the water that passes through the motorised valve then goes into the coiled pipe in the cylinder and NOT actually into the cylinder itself.

 

[dilalio]

Thanks very much for taking the time to explain further, I get it now!

The missing link for me was the water that passes through the motorised valve then goes into the coiled pipe in the cylinder and NOT actually into the cylinder itself.

Don’t worry... that’s the thing that most civvies don’t get

 

[oilboffin]

Now you know you have to swear never to give up the secret of the magic plug and smear yourself in peanut butter and dance round your garden at midnight chanting now I know now I know.

 

[dilalio]

Now you know you have to swear never to give up the secret of the magic plug and smear yourself in peanut butter and dance round your garden at midnight chanting now I know now I know.

Just like us Plumbers do every night in our ritual to the Plumbing god