Central heating drain valve

[LeonR]

Hi,

I have a quick question regarding the drain valve for our CH.
After turning the valve it feels dry and loose and just a few drips of water came out of the outlet, it's probably 20+ years old.
The plumber just replaced the washer and said that was all that was needed.

If I connect a hose to the outlet and start to undo the valve quite a lot of water starts to drizzle out the bottom (I assume it's due to the hose pressure), this does start to get less the more I turn the valve anti-clockwise and water flows out the hose (but still dripping from the valve).

I've not looked at how they work so I assume it's the water flowing around the washer that causes this and it needs to be fully open?

Question is, is this normal? If I keep untwisting will the entire assembly come out of the valve or will it stop turning? If it stops turning then how did the plumber get it out to replace the washer?

I'm scared to keep turning the valve in case the entire assembly comes out and I flood the place.

Thanks!!

Looks like this:

 

[Phill Peck]

Type b drain offs do leak.

Don't take it all the way out you'll get wet.

Just leave a towel under it.

 

[LeonR]

Ok thanks for confirming!

I also noticed that hot water was coming out even though the heating was off (had been for hours), is it possible it shares the same pipework that goes from the boiler to the hot water tank upstairs?

This confused me as I thought the boiler heated the radiator circuits independently to the loop which goes into the hot water tank?

I had to run all of my hot water out of the tank first, I just wasn't expecting this.

Cheers,
Leon

 

[Madrab]

The same water that heats the CH Circuit, also heats the coil in the hot water cylinder to provide hot water, there's a valve that alters the direction of the water flow from CH>HW as demand requires. So if your draining the CH then hot water via the immersion only until it's filled again.
You didn't need to empty all the hot water out of the cylinder through the taps though, if it's only the CH your draining down.

What are you trying to do here??

 

[LeonR]

My plan was to prepare the CH system for some radiator replacements, but first I wanted to put a cleaner in the system for a week to try to clean out what I can in advance.
I'll then drain that away and hopefully have a 'cleaner' system for when I start replacing radiators.

I assumed there would be a valve to control this but I can't see one, at a guess I would expect to see something like this?

Hard to describe but i'll try my best:

Ideal Mexico 2 boiler
4 large pipes come out of that, 1 goes to a manifold downstairs for the rads (where the drain valve is), 1 to the electric pump (I'm not sure what each one does, I can only guess).
The hot water tank has no thermostat on it if that helps describe the age of the system any better? (tank upstairs, boiler downstairs)
Obviously there is a header tank, so vented system (terminology?)
Microbore heating pipes to the radiators

Is it possible to have a system with no electronic valve? Maybe I just have not found it yet?

Cheers,
Leon

 

[it's not that hard]

could have a primatic cylinder,did you just shut off the water and open the hot taps or drain it with a hosepipe, you might have a gravity system are 2 of the pipes that come out of the boiler bigger than the other two

 

[LeonR]

could have a primatic cylinder,did you just shut off the water and open the hot taps or drain it with a hosepipe, you might have a gravity system are 2 of the pipes that come out of the boiler bigger than the other two

I tied the ball float valve up in the header tank (cleaned the tank out as well) and then drained down a little from the CH drain valve.
When I realised the water was steaming (even though the rads were cold) I thought maybe the coil is on the same circuit as the heating, so I just ran hot water on the shower/taps for 5 mins until it ran out, then the water was only warm from the CH drain valve (my logic was the cold water in the cylinder would cool the coil down).

From memory, yes 2 of the 4 pipes are larger.

Something else which confuses me is that the manifold for the downstairs radiators has 8 pipes on it (same pipe with the drain valve), yet we only have 4 radiators downstairs, and I know the upstairs rads come off their own manifold (as I found it under the floor boards).

Cheers for all the help by the way, it helps me a lot!

 

[LeonR]

Also, is there a way I can tell if my cylinder is primatic? The cylinder has a foam jacket and doesn't look THAT old so i'm assuming it's could a coil in it hopefully?

 

[Dan Robinson]

How many tanks in the loft?

 

[dilalio]

Can you post some photos?

 

[LeonR]

How many tanks in the loft?

We have 2 tanks, 1 main and 1 expansion tank.

I've been told because of this it's not a primatic cylinder, which is good to know!

I drained the system today and added the cleaning chemical, thankfully it all seems to be working again! (I was worried about air locks when refilling).

Dan, I have a picture attached, the 4 pipes go to the boiler through the wall.

No 3 way valve and also you can see the 8 radiator pipes coming off the manifold (only have 5 downstairs) , not sure if the others are just capped off under the floor?


Thanks,
Leon

 

[Dan Robinson]

Gravity hot water pumped central heating.

 

[LeonR]

Thanks, that clarify's it

To be honest, i'm not sure the boiler is that efficient but it all works fine, I quite like the character of it, even though all the valves seem stuck and everything I touch starts to drip

 

[dilalio]

As soon as I see paint all over the pipes it makes me swear under my breath

 

[Echo the husky]

As soon as I see paint all over the pipes it makes me swear under my breath

Feel better now?: