Nice drawing. That install is even more cr@p than your original description led me to believe- highly unlikely that 10mm section will supply enough heat to 5 rads without an excessive water speed, only way to get any heat to the far end will be to choke back the lockshields on your existing setup.
It is not satisfactory as it stands- use your new thermometer to get actual rad temperatures (don't mess with lockshields yet, the 'plumber' who installed it all should have balanced it so it operates properly, the fact he hasn't doesn't help his claims of 'its all different now')
Making it work properly;
Best would be to extend your existing 22mm header to the end of the line on the 1st floor (the 10mm sections to the rads will then be short enough for them to work properly). Architecturally that may be impossible or very difficult.
Plan B would be to put manifolds on the end of your existing 22mm, then 15mm legs out - each 15mm leg feeding ideally one, max 3 rads depending on heat loss, ideally all the way to the rad (avoiding hidden joints).
Plan C (might work, might not, depends on the actual lengths of the runs) manifold it in 10mm, 1 pair per rad.
Odds of you getting this 'plumber' to do the work are (I suspect) low. I don't know where you'd go to get an independent assessment of the adequacy of the install, I think this is going to end up in small claims court.
You could ask him how he has determined that 10mm is adequate (he needs heat loss figures for each room- that gives the pipe size required. You also have to consider the resistance presented by each metre of pipe and each fitting to ensure the system is within the capacity of the pump . Handy link here
EDIT NB That link shows calcs for COPPER pipe- bore diameter on plastic pipe is smaller so the numbers will be worse- so in a case where 15mm copper would just do you'd have to fit 22mm plastic or 2 x 15mm plastic.
It is not satisfactory as it stands- use your new thermometer to get actual rad temperatures (don't mess with lockshields yet, the 'plumber' who installed it all should have balanced it so it operates properly, the fact he hasn't doesn't help his claims of 'its all different now')
Making it work properly;
Best would be to extend your existing 22mm header to the end of the line on the 1st floor (the 10mm sections to the rads will then be short enough for them to work properly). Architecturally that may be impossible or very difficult.
Plan B would be to put manifolds on the end of your existing 22mm, then 15mm legs out - each 15mm leg feeding ideally one, max 3 rads depending on heat loss, ideally all the way to the rad (avoiding hidden joints).
Plan C (might work, might not, depends on the actual lengths of the runs) manifold it in 10mm, 1 pair per rad.
Odds of you getting this 'plumber' to do the work are (I suspect) low. I don't know where you'd go to get an independent assessment of the adequacy of the install, I think this is going to end up in small claims court.
You could ask him how he has determined that 10mm is adequate (he needs heat loss figures for each room- that gives the pipe size required. You also have to consider the resistance presented by each metre of pipe and each fitting to ensure the system is within the capacity of the pump . Handy link here
EDIT NB That link shows calcs for COPPER pipe- bore diameter on plastic pipe is smaller so the numbers will be worse- so in a case where 15mm copper would just do you'd have to fit 22mm plastic or 2 x 15mm plastic.
