Zoned central heating problem

[leethegasman]

Hi,



I was told that it was a dual zone system and it was installed only 3 months ago, but there is a problem. When I switch a zone off i.e. upstairs ,the rads still get warm in that zone, once the other zone (downstairs) comes on and vice versa.


Fred.

Can I just ask when you have one room stat on and one off do both upstairs and downstairs radiators get hot.if this is the case take no notice of my post.but if when you turn on your downstairs room stat your upstairs radiators come on.and when you turn on your upstairs room stat your downstairs radiators come on
The reason I am asking I can not tell from your post.if this Is the case the room stats are controlling the wrong zone and is a simple fix.

 

[fredfat]

Hi Tony,

I will be speak to installer tomorrow and will be requesting that he comes back and fits a bypass circuit with an automatic bypass valve as it seems he should of done in the first place !

As you have mentioned about the pump being inside the case I'm i right in thinking that i'm not allowed to remove the case?

Once again many thanks for your time and help with this

Fred

 

[fredfat]

Hi leethgasman, thanks for your reply, the room stats are controlling the correct zone valves it is just that all the rads are getting heated instead of just the zone that is requesting heat. I think with the help of Tony and Croppie the problem has been found to be the lack of a bypass valve on the system and potentially the pump being set to fast.

Fred

 

[fredfat]

Hi jam1979, thanks for your reply as you may see from other post's it seems as thought the problem has been identified cheers

Fred

 

[fredfat]

Your boiler has something called pump overrun which protects the boiler. An automatic bypass provides a route for the water to flow when the zone valves are closed.

You've definitely a combi yes? And a hot water cylinder?

Your house doesn't sound huge! Two bedroom?

Hi Croppie,

Thanks for your help looks like you where spot on, will be speaking to the installer tomorrow and getting him back to install an autobypass as per yours and Tony's and installation manuals advice. Cheers

Fred

 

[Nostrum]

Zones valves on flow, bypass fitted. Jobs a good un. Sounds like its not necessarily caused by circulation. Heat rising into a few of the radiators upstairs. Do they get roasting hot, or warm on top? How long do they take to warm up if only downstairs zone is on?

 

[fredfat]

Hi Nostrum ,

thanks for your reply, my system and problem is Ideal combi boiler 30, 3 rads upstairs 3 rads downstairs. Controlled with wireless enabled 2 zone programmer and 2 wireless room thermos. There are 2 x 2 port motorised valves on the RETURN pipes.

When I switch a zone off i.e. upstairs ,the rads still get warm in that zone, once the other zone (downstairs) comes on and vice versa.

The rads upstairs don't get as hot as down stairs but they get warm fairly quickly. I don't think the water is being circulated as such in the zone thats switched off as the return pipe remains cold. The same thing happens if upstairs on and down stairs off with the exception of 1 rad that i think is the last in the system

Fred

 

[fredfat]

Hi,

Just quick update spoke to Engineer this morning and he is going to come out and look at the problem. No mention of not enough rads ! so fingers crossed he has forgot about using that as an excuse. I will let you know how it goes. cheers

Fred

 

[rob2048]

Hi your zone valves are on the flow not return pipes if they have used one return pipe and not two separate returnes the hot can creep up the one that is turns off we have had this now we always run two seperate returns and link in just before boiler hope this helps

 

[fredfat]

Hi Rob, thanks for your reply, the valves are defiantly on the returns and there are 2 returns 1 for each zone. Cheers

Fred