Issue
Can the DC1100 / DC1400 serve more than 2 boilers
Environment
DC1100
DC1400
Cause
Can the DC1100 / DC1400 serve more than 2 boilers?
Resolution
The DC1100 or DC1400 is primarily designed for a 1 or 2 boiler installation.
However in the case of 3 boilers. Note, 2 additional relays are required:
Wire Boiler 1 to Boiler 1 terminals.
Wire Boiler 2 to Boiler 2 terminals.
Wire the coil of the 1st 230Vac relay to Boiler 1 terminals.
Wire the coil of the 2nd 230Vac relay to Boiler 2 terminals.
Either wire the relay contacts in parallel or in series, the feed for each contact will be wired from the Boiler 1 and Boiler 2 terminals respectively on the controller, the output of the relay contacts will be wired to Boiler 3.
This is a workaround and does have its disadvantages: Boiler 3, when wired in parallel will always be a Lead Boiler and will do more work or when wired in series it will always be a Lag Boiler and will do the least work.
In the case of 4 boilers:
Wire the boilers in pairs to each boiler output on the controller. Note, the boilers will lead or lag in pairs.
In the case of 5 boilers:
Adapt both the solutions above.