y plan heating (combiboiler)

[The apprentice]

hi there thanks in advance for helping was just wondering if anyone had diagrams of y plans which i think are combi boiler wiring diagrams

 

[Deleted account]

Not combi boilers. System boilers.
system boilers do heating and a hot water tank.
y plan for systems with a3 port valve
s plan for system with two 2 port valves.
just google it loads of images pop up.

 

[The apprentice]

had a little look just want to know how the water works is it a flow switch that fires the boiler

Not combi boilers. System boilers.
system boilers do heating and a hot water tank.
y plan for systems with a3 port valve
s plan for system with two 2 port valves.
just google it loads of images pop up.d

 

[Deleted account]

had a little look just want to know how the water works is it a flow switch that fires the boiler

No . Its the programmer that controls the firing of the boiler via room stats for rads and water cylinder stat for the stored hot water.

 

[Deleted account]

To add to the above

call for hot water from programer.
signal sent to port valve Via cylinder stat.
If the temp in cylinder is lower than set temp signal is allowed through.
port valve opens to allow water to flow to the cylinder.
port valve sends a signal to pump and switched live in boiler firing it up.

 

[telectrix]

try these for starters.

 

[snowhead]

had a little look just want to know how the water works is it a flow switch that fires the boiler

Yes with a Combi Boiler the flow of water through the Hot tap(s) activates a flow switch in the boiler to fire it up for Hot water only.

 

[SparkySy]

Honeywell do a boiler book that used to be free on request from them that has most combinations of boiler systems,programmers and stats in. (Think mine is issue 23) it has been a very handy book over the years and well worth a call to them!
Sy

 

[snowhead]

Pdf of above book,

https://heatingcontrols.honeywellhome.com/documents/All/pdf/Heating-Controls-Wiring-Guide-Issue-18.pdf

 

[SparkySy]

Just found my copy and it's issue 16 not 23
?

 

[DefyG]

Going 'off piste' slightly from OP's question, I have come across 'Hybrid' systems a while back where combi boilers were used in conjunction with a hot water cylinder.
Don't recall it overly complicated in terms of wiring at the time.

 

[The apprentice]

Thanks a lot guys

 

[johntheo]

Going 'off piste' slightly from OP's question, I have come across 'Hybrid' systems a while back where combi boilers were used in conjunction with a hot water cylinder.
Don't recall it overly complicated in terms of wiring at the time.

Saw a few posts where people wanted to use their combi with cylinder only (and rads) but the advise was to still leave the combi HW side serving one outlet only like the kitchen tap, don't know if the HW side can be de commissioned completely or not, safely.