What's best way to see which radiators are in series

[electrofelix]

Had the evohome I place for a few years now, and for once while it wasn't quite cold enough for most rooms to need heat, needed to bring one specific radiator on to help dry some clothes a bit quicker.

Unfortunately the radiator ends up not coming on. Looking via the control panel, I could see the valve was reporting 100% open, but no heat.

The most likely problem is one that was overlooked at the start, some of the radiators are actually in series, so when they come on the other radiator valves in the path need to open up as well or the water just doesn't get from the boiler to the radiator. Since most doors are slightly ajar, usually more radiators would be working at the same time when it's cold enough keeping the house comfortable enough for us not to really notice this before now.

Is there an efficient way to work out which radiators in different should effectively be in the same zone in order to allow any of the rooms needing heat to receive it?

I could just increase the temp on each radiator downstairs in turn waiting 10 minutes between and then check when the radiators are actually getting warm and then do the same upstairs, and then go back through them removing other radiators to work out the connections. Just struck me as quite time consuming and I'm wondering if there is a better way?

[Richard]

Radiators are normally piped in parallel. Never seen radiators piped in series. Even one pipe systems allow flow to the next radiator?

Have a chat with your heating installer to seek a solution.