Joined: 22 May 2005 Posts: 342 Location: West Devon
Posted: Tue Apr 12, 16 3:49 pm Post subject: Understanding a plumbing/heating system.
I'm trying to make head or tail of a customers heating system. To start with its a fairly standard Y plan with gravity fed hot water tank. Fine so far. Add to that a solar coil in the bottom of the hot tank - also fairly standard. In place of a boiler there's a remote pellet boiler and it own tank... but that's kind of transparent to the main system. Any call for heat which the Y plan system sends just circulates hot water from the pellet boilers own tank to the three port valve. The pellet boiler just self manages to keep its own tank hot.
Then there's the confusing bit. There is another coil in the main hotwater tank, combined with a pump and valve which can pump C/H water through the tank coil and the heating circuit. This has its own timer/programmer. The customer has no idea why its there or what she should set the timing for. I can see this subsection could help ditch excess solar heat into the radiator circuit... but why would this need a programmer? The installer helpfully labelled the controller 'HA'. So what does HA stand for and why does it need a timer programmer?