balancing central heating

[benjamin31]

Hello,
I have just installed new pipework for a central heating system. It was formerly a one pipe system, and has now been changed to two pipe, with 3 extra rads to previously.

I have been balancing the system, but by the time i reach rad number 6 or 7 the boiler shuts down. I have the room stat set at 30 while i've been doing this.

Is it possible that the room stat needs replacing, or should i increase the pump speed? It's currently set at 2 out or 3.

Cheers for advice.

 

[Nixt]

Does the boiler permanently shut down or just whilst it reaches temp on it's own control stat?

 

[benjamin31]

No it doesn't permanently shut down, just goes back to pilot. It only takes ten mins though. I guess it is summer though. However, when I turn the room stat it clicks at 22. If I turn it to 30 it doesn't make the boiler fire up. The room stat is old, and could be full of dust, could this be affecting it's operation?

Cheers

 

[Nixt]

Check the boiler control stat setting then flow pipe does not get too hot. If heat is unable to dissipate quickly boiler may reach temp too early.

 

[gas4you]

Check pump isn't stuck, any zone valves you have fitted are wired and working correctly and the rad locksheilds are open fully to start with.

 

[benjamin31]

Hello.
Thanks for advice so far.

The pump isn't stuck, and I didn't need to install new zone valves, the existing ones were working fine.

I'm not sure where the boiler temp control is exactly!

There is a bypass fitted with a gate valve on it. I fitted the rad in the hall (same room as room stat) without a TRV, so maybe I can close the gate valve on the bypass now?

Would turning the pump up to full speed, and replacing the old room stat make a positive difference?

Thanks

 

[megawatt]

With all the rad lockshields open fully (i.e. before you started the balancing) did the radiators all heat up okay?