Heating System connections

[cruelty]

Right here goes, doing a heating system which involves

time clock (3 Zone)
Zone 1 Living area heating
Zone 2 Bedroom Area heating
Zone 3 Hot Water

2 room stats controlling above heating
1 tank stat controlling hot water

2 motorized valves (living + bed)
hot water is a pressurised system

1 pump

system has also solar panels and back boiler

have it all wired and now need to 2nd fix, i have it all up and going perfectly except for back boiler and solar panels

problem is when back boiler heats to 50 degrees i need to fire the pump and open both motorized valves without firing the boiler

any help appreciated

 

[Graeme Harrold]

Its all going to be in your timer info as to whether this can be done with the unit you have. All of the input circuits work on LOGIC, either they are on or off, and based on the inputs, the output is normally pre determined.....................

Are you saying you have 3 heat sources, a std boiler, back boiler and solar????

 

[cruelty]

yes i have oil boiler, back boiler(open fire) and solar

 

[Deleted member 9648]

Run the oil boiler supply through a pipe stat on the back boiler flow pipe, Pipe stat to break on temperature rise which will prevent the oil boiler firing....valves and pump can operate as normal through the room stats,the pipe stat will just determine which boiler is providing the heat.

 

[Graeme Harrold]

Without seeing what you have done, can you input the back boiler stat to the timer on the same circuits as the oil boiler. In esscence parallelling the stat connections so that the pump works on a signal from the oil boiler stat and/or the back boiler stat. The two valves are operated depending on whether the heating or water switch positions.

After thought: heating off, and fire lit, is there a fail safe for the back boiler?

Run the oil boiler supply through a pipe stat on the back boiler flow pipe, Pipe stat to break on temperature rise which will prevent the oil boiler firing....valves and pump can operate as normal through the room stats,the pipe stat will just determine which boiler is providing the heat.

devils advocate, but would the water from the iol boiler potentially flow through the back boiler pipe work, not necessarily pumped flow , but convection flow???

 

[Deleted member 9648]

Back boilers have to be connected to an unrestricted gravity circuit....normally the H/W cylinder ,this is the failsafe . The pumped heating circuit is separate,excess heat from the fire circulates round the gravity system and heat can also be pumped around a heating system as required....a pipe stat could be used simply to switch off the oil boiler when the back boiler is providing heat. There are no stats or controls on a fire back boiler so you cant parallel with the oil boiler stat.

 

[cruelty]

Run the oil boiler supply through a pipe stat on the back boiler flow pipe, Pipe stat to break on temperature rise which will prevent the oil boiler firing....valves and pump can operate as normal through the room stats,the pipe stat will just determine which boiler is providing the heat.

cheers man understand that perfectly now, is there any way to do it so the time clock or stats are not on at all and when the back boiler flow pipe reaches the desired temp it will open both valves and fire pump??

think plumber has told customer this is the way it works

maybe it's impossible just wondering

 

[Deleted member 9648]

Yes,if you fitted a second pipe stat to make on temprature rise fed with a permanant live,use that to energise a 2 pole relay and run a supply to feed the brown valve wires through separate poles of the relay.That way you can open both valves independantly of the stats without backfeeds when the system is working on the oil boiler. Not sure why you would want to do that though,the rooms will get very hot without any control when the fire is on....and the plumber must have incorporated an unrestricted gravity loop into the backboiler to lose excess heat,you cant rely on a pumped circuit with valves on to do this......fire on....power cut...KERBOOM