Is there a limit to the number of radiators you can have in a system? Can I run 9 rads from a 15mm pipe, if everything else in the house is 15m or microbore? I read in one of the B&Q leaflets you should only use 3 rads from 15m. I already have a bunch of 15m pipework to one rad, but to replace it with 22mm would mean ripping up the floor. What happens if I extend it and add the extra rads (8) I need? Do the rads just take longer to warm up or what? Kind Regards, Shane Cook.
No is the simple answer...The total heating load must match the heat input and flow rate! Depending on the size of the total radiator surface it is unlikely that 15mm pipe would be adequate to supply 9 rads. The consequence would be that the rads never get hot because the rad would lose heat to the air faster than the flow of hot water could heat the rad
as bilco said, no chance of 15mm running 9 rads. the just wouldn't heat. even if u try to balance the system correctly there just wont be enough hot water to go round 9 of the smallest rads. no luck mate u will have to re do pipes, sorry