Change of Pipe Size in C/H system

[pacorio]

Hi all and thanks in advance for any help offered. I have just purchased a new home which is actually quite old - forgive the pun. The property has a combi boiler and the radiators are all fed via 15mm piping. Upstairs radiators look neat as pipes are under the floor. But downstairs the pipes come down the middle of the walls!! ie they have not been buried in the wall. My question is this: Can I connect microbore piping to the upstairs flow and returns and change the lockshields to suit the worst of the downstairs radiators. - this will enable me to bury the pipe in the wall or at least re route it. Really appreciate your help - thanks in advance please be gentle this is my first posting!!

 

[flyboy]

I dont see why not, sure someone with more experience will tell you if its not OK.

 

[WHPES]

I take it you can't chase the 15mm into the walls? I really don't like microbore. The pump has to work harder and they are more likely to get blocked. I'm sure others will disagree but that's my stance.

 

[secret squirrel]

To be honest, everytime I have to work on micro bore it worries me, blockages, airlocks, I'd change micro bore for 15mm not the other way round but thats only my opinion.

 

[migoplumber]

central manifold of 22/28 to middle of house then microbore from a manifold. best sytstem in the world imho

 

[moogwai]

microbore in my opinion is a bag of shoite.....stick with 15mm and try and drop them in a corner of a room somewhere so it's not as obvious to see and box them in and decor the box.

 

[Blackcatgas]

central manifold of 22/28 to middle of house then microbore from a manifold. best sytstem in the world imho

Heats up quicker too, nothing wrong with installing microbore from scratch on a new install, then make sure theres plenty of x100 in it, good as gold.

 

[stevetheplumber]

i agree microbore is a good system if installed and maintained properly

 

[fuzzy]

i agree microbore is a good system if installed and maintained properly

IMO -Depends on the type of install and size of property

 

[LIFES A GAS]

I have to say most positive coments for microbore seem to comes from installers, why? in general they fit & forget, they dont aways see the big picture when things go wrong, I have been working in the service/repair side of the industry for 40 years +, I have seen far more problems with microbore than with 15mm drops, like it has already been said, 15mm drops in corners or behind curtain line if done right are hardly noticable and one drop can supply more than one radiator, this is just my opinion.
Martin

 

[migoplumber]

as for maintenance, only maintenance really to any pipe system is flushing and dosing. cant see an easier way of doing that, than isolating each rad in turn from manifold !
other problem could be householder nailing through the pipe - again easily isolate just the one rad as opposed to the whole system !

 

[Blackcatgas]

I have to say most positive coments for microbore seem to comes from installers, why? in general they fit & forget, they dont aways see the big picture when things go wrong, I have been working in the service/repair side of the industry for 40 years +, I have seen far more problems with microbore than with 15mm drops, like it has already been said, 15mm drops in corners or behind curtain line if done right are hardly noticable and one drop can supply more than one radiator, this is just my opinion.
Martin

I agree with you, microbore will cause more problems than 15mm +, if you dont look after it properly. A well designed and maintained system will last.

 

[WHPES]

Whenever I get called out over radiators not working in my local area it is more often than not supplied by microbore pipe.

 

[fireblade]

When i piped my house i did all rad drops in 10mm i put them in plastic trunking teporary now when i strip a room and re plaster i just take them out the trunking and put them behind the plasterboard also i made a manifold sytem that feeds each room with its own two port valve and every room has a programmable room stat no trvs and i am running a grant oil boiler and ferroli 150 un vented cylinder the heating and hot water cost for the year is £400 eg 1000 litres i am gas safe registerd but I am glad i have oil

 

[LIFES A GAS]

That must have been a challenge wiring up all those zone valves Fireblade but it proves the point that you cant beat having good contol over any heating system, just wonder how much it would cost to run if you had gas?
Martin.

 

[fireblade]

should be quite good with gas about £400 worth of controls but could probably use an underfloor manifold might of been easier and take up less room