Hello all, I have a question and have searched by cannot find an answer.
I have a combi boiler in my house, I was wondering how it works.
When you open a hot tap, the boiler fires up and hot water is shortly deliered at the hot tap.
My boiler has no intermittent or perm pilot btw.
My question is how does the boiler operate to firing, is it like this, or am I way off.
I'd be grateful to anyone who can help me.
Hot water tap opened
Water flows through diverter valve (if combi boiler has 1)
Diaphragm lifts (if this type of diverter valve)
Port closes to main heat ex and allows water to flow through DHW heat exchanger (plate heat ex etc, if this type of combi)
Spindle raises and makes contact with micro switch
Pump runs
Pump flow switch is activated
Fan runs
Air pressure switch proves fan is running ok, flueways are clear, air pressure hoses/ports are clean/not blocked
HW thermistor/stat is calling (within set range)
Ignition/gas valve opens
Gas flows through to burner
Gas ignites
FSD probe senses gas and proves back to board
Gas valve opens at full rate until stat/sensor up to temp/demand satisfied
and the PCB is the electronic part which receives signals (voltages) and allows firing sequence to move onto next part if all Ok
All this happens in a split second or so
I know some combi's don't use the pump with HW but a lot do.
I have a combi boiler in my house, I was wondering how it works.
When you open a hot tap, the boiler fires up and hot water is shortly deliered at the hot tap.
My boiler has no intermittent or perm pilot btw.
My question is how does the boiler operate to firing, is it like this, or am I way off.
I'd be grateful to anyone who can help me.
Hot water tap opened
Water flows through diverter valve (if combi boiler has 1)
Diaphragm lifts (if this type of diverter valve)
Port closes to main heat ex and allows water to flow through DHW heat exchanger (plate heat ex etc, if this type of combi)
Spindle raises and makes contact with micro switch
Pump runs
Pump flow switch is activated
Fan runs
Air pressure switch proves fan is running ok, flueways are clear, air pressure hoses/ports are clean/not blocked
HW thermistor/stat is calling (within set range)
Ignition/gas valve opens
Gas flows through to burner
Gas ignites
FSD probe senses gas and proves back to board
Gas valve opens at full rate until stat/sensor up to temp/demand satisfied
and the PCB is the electronic part which receives signals (voltages) and allows firing sequence to move onto next part if all Ok
All this happens in a split second or so
I know some combi's don't use the pump with HW but a lot do.