Is there a plumber in the house...?

[cptncrackoff]

I ranted yesterday about the heating being stuck 'on'.

I'm after a little help.
I have removed the cover off the thermostat, its an old dial type, ACL.
With it on 0c most of the radiators now stay cool... however...

There are two pipes next to each other all the way round the house, when the hot water is on, one stays cool, the other gets hot....
They go up in the roof... (bungalow).... then re-appear in the bathroom still with one hot and one cold then the hot pipe goes into the bottom of the bathroom radiator, slowly heating it up.

The hot pipe also goes into and out of the kitchen rad, and the hallway rad and slowly warms these as well.

If there are any plumbers here, does this sound right?

I've only got the rads in the lounge and bedrooms where the cold pipe goes into the radiator, the others are warming up?

Would any pictures help?

Many thanks for anyone that can offer any advice !

[bearded bloke]

You need a Potty he will doubtless be along later,in the meantime is that a boiler stat or a room stat ?

[Potstubsdustbins]

Evenin All.

Sounds like this could be an old (no very old) I last installed this way when I was in my twenties single pipe system and that the thermostat controls the pump. And that the problem could be that with the pump switched off the radiator circuit is working on gravity.

A few questions first.

What type and make of boiler including fuel.

How old is the system.

Are there 4 pipes coming from the boiler 2 to the hot water cylinder and 2 for the heating.

If its a wall hung boiler a pic showing the boiler and pipes would be very helpful.

Potty

[Potstubsdustbins]

You need a Potty he will doubtless be along later,in the meantime is that a boiler stat or a room stat ?

Room stat ACL Drayton.

Potty

[cptncrackoff]

Hi, sorry I got dragged to T@sco! - yes apparently it does take 4 hours...

The boiler is a gas myson economist, i believe late 80's early 90's...

there is one cold water feed into the bottom of the boiler, two pipes coming out the top of the boiler and going into the loft approx 1".

In the loft there is a pump (which the last time we had the boiler serviced the guy said he had to turn the pump up to max... the boiler was making alot of noise and this stopped it, he did say it like having it on the max setting wasn't a good thing!?)

2 foot away from the pump there is some sort of electrical diverter... 'tower valve mv2-22c, 5 watts then the pipes disappear downwards to the airing cupboard where there is...

1 x 1/2" (roughly) cold water pipe, that goies straight past the tank to the loft.
1 x 3/4" ish cold pipe that again goes up to the loft.

1 x 3/4" ish hot pipe that comes down and goes into the bottom of the tank
1 x 3/4" ish hot pipe that comes down and goes into the tank halfway up
1 x 3/4" ish hot pipe that comes down, tees off to the top of the tank and goes off somewhere else...

Perhaps pictures are called for!?

I'm not thinking there is anything wrong with the thermostat now - it 'clicks' at about 22c ish ... not that i actually know what i'm talking about!

[bearded bloke]

2 foot away from the pump there is some sort of electrical diverter... 'tower valve mv2-22c

Straight through or Tee ??

[cptncrackoff]

straight through by the looks of it, its not very easy to get to... i did get a photo....

[cptncrackoff]

I took some photo's in case this was the offending article...

[Potstubsdustbins]

Pictures would help.

Little confused at the moment the divertor valve number you quote is for a 22mm 2 port valve i.e. 2 pipes only. Manufactureres requirements for the Economist ask for a 3 port valve or two 2 port valves.

The two pipes that come of the top of the boiler are the water flow and return pipe's The flow hot water away from the boiler and the return cool water back to the boiler for reheating. The 15mm to the bottom of the boiler is most likely the gas supply pipe.

Presuming it is not a sealed system which is doubtful.

Correctly piped up the flow should go up from the boiler in 22mm the first connection should again be 22mm this is the 'open vent' to take expansion waters over the small feed tank in the loft. The next connection should be a 15mm pipe the 'cold feed' this brings system top up waters from the small feed tank into the system.

Next is the pump, after that should be a 15mm valved pipe leading back to the boiler return a 'bypass' but I don't think you will have one of these thats why your boiler was noisy.

Then the 22mm flow pipe should divide either using a 3 port valve or a tee, if its a tee there should be a 22mm 2 port valve on each leg/pipe. One leg is for hot water (to the cylinder) and one for heating (radiators).

The hot water pipe should go into the connection mid height on the cylinder, the pipe off the bottom of the cylinder (return) should go all the way back to the main boiler return and tee in as the last connection before the boiler.

If you google Myson Economist you will find the installation instructions are there in PDF with a good line drawing which might be easier to understand than my ramblings.

From your 'rant' I remember you saying you cannot have hot water without heating. As the system always been like this (please say no) or has this fault just occured..

Colin

[Potstubsdustbins]

Just seen your pics is that tee we can see between the boiler and the valve?

Colin

[Potstubsdustbins]

Be careful that tee has a weak joint where you can see the white powdery scale, Wouldn't want a messy flood.

Colin

[cptncrackoff]

I'll have a look at the diagram and take a few pictures.

The pipe after the pump is tee'd but i can only find one 2 way valve up there, but I'll have to look again, and more pictures as well...

last summer i turned the thermostat to the lowest setting, i think its actually 10c rather than 0c, and i'm 99% sure that the rads were all cold.

I'll gather more pictures!

As you can tell, i'm not entirely clued up on this, when i said i cant have hot water without heating i meant now, as in when you turn the boiler on to heat the water...the radiators all heat up.
However when you have the heating on, the system has always heated the hot water as well, you cant have one or the other, if that makes sense!

[cptncrackoff]

Just seen your pics is that tee we can see between the boiler and the valve?

Colin

nope that tee is between the pump and the valve

[Potstubsdustbins]

Yep good sense.

OK from what I can see some one has done a cheap job. The two port valve will be on the heating/radiator circuit and it will be control by the room stat. The other pipe that comes from the tee will go to the flow connection on the cylinder.

It works like this. The time clock comes on and makes a live connection to the boiler and pump, the boiler fires and the pump runs to supply the cylinder with hot water.

If the time clock is a 2 channel type i.e settings for hot water and heating when the heating circuit is switched on this will supply a live to the room stat and this will control that valve. If the clock is a single channel type you will have to turn the heating off and on at the room stat.

Either way at this time it sounds like your two port valve is buggered. If it was just the internal electric motor it would fail to open and supply hot water to the rads. I think that the rubber paddle in the body of the valve has perished and is allowing hot water to pass to the rads.

Have a good look tomorrow take a couple more pics and I am sure we can nail it.

Colin

[Potstubsdustbins]

Bet you wish you were fishing. LOL

Potty