why can't i just use solenoid valves hooked to a small bank of relays(using relay logic to control operation) connected to thermostats to control a multi zone boiler system? it would work, but can i do it, why must i use expensive zone valves?
Its just an educated guess but I would say it would cause system shock if a valve just snapped shut as against closing gently. Assuming the system was shutting down as a zone valve shuts the control switch opens and turns off the plant whilst the valve is still partly open. With a solenoid unless you fit a timer to pre shut off the plant then shut off the solenoid you would probably cause some plant damage. Also by the time you have wired all that lot up you may as well do the job with a zone valve.
