Water also heating Radiators

whiskywhisky

Hi

Would be very grateful for some advice.

Moved into a new house which has a very old heating system, it is an ideal mexico 2 floor standing unit which heats the cylinder for water and radiators. Anyway once we put just the water on, the radiators are also warming up - this is fine now but obviously will not be in the summer.

We a couple of weeks ago had a specialist company in to service this. He mentioned that it is in good condtion for its age and when asked he said that heating the water with radiators also heating up is correct. He did try to explain this, something to do with gravity system and the water is being pushed about all the pipes. Most of his info went way above my head, I have since tried to read up online but everywhere seems to suggest that the water and radiators are heated independently.

I guess what I am asking is should I get a second opinion? or are older systems plumbed in such a way that both heating and water working together?

The system has seperate dials to turn on the water and heating, and we are turning on just the water.

Thanks

ariba10

Is it the upstairs rads only that are heating up or all of them?

whiskywhisky

ariba10 - I will double check when I get home from work. Thinking about it I am pretty sure they are hotter upstairs. Sorry to sound like a real numpty on this, but in my defence I have lived most of my live in a hot air system house.

Thanks

macman

All you have to do in summer is turn off the rads, and drop the room 'stat to it's lowest seting, if fitted.
Gravity-fed CH was common until the end of the 1960's.
You may have a manual gate valve to isolate the flow to the CH circuit, have you checked? Look in the airing cupboard near the hot tank for starters.

n_s_simpson

If it's just the upstairs rads, I believe that's totally normal. Turning the heating on will pump the water down to the downstairs rads too but when switched off will still allow the water to flow around just the upstairs rads.

That's what our old rented house did and our house did until I had everything ripped out and repaired for a sparkly new combi system.

macman

Hot water rises, basically. Cold water sinks to the bottom.

whiskywhisky

Thanks will check whether upstairs are hotter later tonight.

Regarding the "manual gate valve", just to clarify am I looking to check whether there are 2 of these (maybe near the cylinder) and if there is I turn off the 1 not going into the cylinder?

Many thanks

keystone

Whilst you are ferreting about check whether your system configuration looks like this:



which is gravity HW and pumped CH (perhaps as macman has suggested it has no pump at all). The systems you have discovered on teh interwebz probably look like this:



which is fully pumped and CH (nearly) independemt of HW. You really should consider getting the system upgraded to fully pumped. Not only is it more efficient you also have far more control.

When you get people in to quote for this then ignore all the sucking of teeth and shaking of heads that will occur when the old Mexico is spotted. Old it may be, inefficient (in terms of modern boilers) it may be but its incredibly reliable and will go on and on for years giving rise to far less maintenance (= cost) that a modern one will require. Although its not very PC in terms of "carbon footprint" your additional gas usage with this old girl will cost far less than the maintenance of one of the new "jumps through hoops, super efficient" modern jobbies. Keep the Mexico as long as you can.

Cheers