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You will have to bear with me as I have never had central heating before and aren't used to setting thermostats and timeclocks, what overrides what and how it is "normally" run.
My "plumber" says what I want "cannot be done", but based on his previous history I think it may be more bullsh1t he's telling me.
So.. there is a timeclock that has Water on/off (etc) and Heating on/off (etc) (keep the options simple for clarity).
There is a worcester oil boiler with a thermostat and pump to-from the ACV tank in tank thermal store.
The thermal store itself with a thermostat in the SECONDARY water, note NOT sensing the primary, only the tap water so to speak.
Finally there is the central heating pump, circulating the same PRIMARY water as goes through the oil boiler and the ACV tank in tank.
Operation as it stands..... Hot water side....
I set the required temp in the tank on top of the tank itself and the oil boiler cranks up and heats the primary water until the boiler thermostat trips out and stops the boiler but the pump keeps going because the secondary water isnt up to temp. The pump keeps running all the while until the heat transfers across to the secondary water, cooling the primary water which in turn brings the boiler back on again. This cycling carries on until the secondary water is up to temp and the thermostat on the tank kills circulation pump and overrides the oil boiler thermostat. The timeclock will just switch the obove system on/off.
All normal?
Central Heating Side...
This is where I can't get my head around it... The room stat calls for heat and turns on the central heating circulation pump and the oil boiler circulation pump but the oil boiler won't fire up because the thermostat that is in the SECONDARY water says "I am up to temp". So the pumps run and run, dragging the temp of the secondary water down until the said stat says to the boiler .. "ok" and then it kicks in.. and the oil boiler fires up.
What I cannot understand is why the room stat cannot just start the boiler, or is that not possible? I understand the stat in the boiler has to cut it off when it reaches temp, but does the stat in the secondary water in the tank have to effectively "control" whether the central heating can come on? Surely there is a better way, leave the secondary water at the required temp and just kick the oil boiler in?
Timeclock again just tells the above when to happen.
Am I asking for the impossible as the "plumber" would have me believe?
He was talking about feedback to the controller as both sides are trying to control the same pumps??
.
.
.
You will have to bear with me as I have never had central heating before and aren't used to setting thermostats and timeclocks, what overrides what and how it is "normally" run.
My "plumber" says what I want "cannot be done", but based on his previous history I think it may be more bullsh1t he's telling me.
So.. there is a timeclock that has Water on/off (etc) and Heating on/off (etc) (keep the options simple for clarity).
There is a worcester oil boiler with a thermostat and pump to-from the ACV tank in tank thermal store.
The thermal store itself with a thermostat in the SECONDARY water, note NOT sensing the primary, only the tap water so to speak.
Finally there is the central heating pump, circulating the same PRIMARY water as goes through the oil boiler and the ACV tank in tank.
Operation as it stands..... Hot water side....
I set the required temp in the tank on top of the tank itself and the oil boiler cranks up and heats the primary water until the boiler thermostat trips out and stops the boiler but the pump keeps going because the secondary water isnt up to temp. The pump keeps running all the while until the heat transfers across to the secondary water, cooling the primary water which in turn brings the boiler back on again. This cycling carries on until the secondary water is up to temp and the thermostat on the tank kills circulation pump and overrides the oil boiler thermostat. The timeclock will just switch the obove system on/off.
All normal?
Central Heating Side...
This is where I can't get my head around it... The room stat calls for heat and turns on the central heating circulation pump and the oil boiler circulation pump but the oil boiler won't fire up because the thermostat that is in the SECONDARY water says "I am up to temp". So the pumps run and run, dragging the temp of the secondary water down until the said stat says to the boiler .. "ok" and then it kicks in.. and the oil boiler fires up.
What I cannot understand is why the room stat cannot just start the boiler, or is that not possible? I understand the stat in the boiler has to cut it off when it reaches temp, but does the stat in the secondary water in the tank have to effectively "control" whether the central heating can come on? Surely there is a better way, leave the secondary water at the required temp and just kick the oil boiler in?
Timeclock again just tells the above when to happen.
Am I asking for the impossible as the "plumber" would have me believe?
He was talking about feedback to the controller as both sides are trying to control the same pumps??
.
.
