Help With Heating System, Please!

[cruelty]

hi,

system has 2xCH & 1xHW Zones

system also has solid fuel back boiler

system has 2x CH Motorized valves

Garage = Oil Boiler & Pump (No over-run)
Hotpress = Cylinder, 2 motorized valves, CH circulating pump & Back boiler pump, cylinder stat, back boiler stat

so there is 3 zone time clock (2x CH & 1xHW)
2 CH room stats


what i need to happen:
CH1 turned on = fire Boiler + pump(garage) & Circulating pump (hotpress) & open corresponding "MV"
CH2 turned on = fire Boiler + pump(garage) & Circulating pump (hotpress)& open corresponding "MV"
HW turned on = fire Boiler + pump(garage)
Back boiler when lit = opens both CH motorized valves & fires Circulating pump(hotpress) 

I need a wiring diagram for this system

if you could be so kind to help me out i would be forever grateful

 

 

[Blue Duck]

Search "honeywell wiring guide" this may give more info on what you seek.

I'm not too hot on CH wiring this guide has helped a great deal in the past.

 

[cruelty]

hi thanks for your reply, however nothing including back boiler etc

 

[Andy™]

could be done by a feed from back boiler bypassing controls and going direct to the valves / pump. may need a relay in that to stop the signal to the oil boiler though. and you do know there must be a radiator that is gravity and doesnt rely on the pump / valves, dont you

the wiring guide as above will help you. but what you want is not standard so you would need to use the wiring diagrams and make your own adjustments to them

 

[ProDave]

Back boiler systems are notoriously difficult to get right.

HOW is the back boiler connected to the rest of the system? Neutraliser? direct into the HW tank?

You will need something to detect when the BB is fired up. Pipe stats don't work very well for this. The best thing I have found is a flue thermostat.

Wire the system first jut as a conventional heating system. Then add a relay (driven from the flue stat) to so the necessary overrides and to inhibit the oil boiler firing up.

Remember to take precautions to prevent over heating / boiling, for instance an over temperature thermostat on the tank that opens all valves and turns on all pumps to dump heat.

 

[cruelty]

Back boiler is connected direct into HW cylinder,

Can you supply wiring diagram to connect up as "conventional heating system" including what i have described in "OP"

thanks

 

[Sharpend]

I thought you have said that you have wired many conventional heatings?

 

[cruelty]

yes i have but all different from this, i have done underfloor heating systems, also geothermal systems etc

 

[Andy™]

well if you have wired many and have an understanding of how they work, then this should be reasonably easy. ive already told you the basics of what you need to do, as have others. make a diagram of the wiring for the system excluding the boiler (this part should be easy). then add back boiler on feed to relevant parts to achieve what you want

or at least try it yourself, post diagram and someone will tell you if its right or any problems with it

 

[SPECIAL LOCATION]

[SIZE=10.5pt]Why is it that when Central Heating / or Boilers or other such similar devices are mentioned in a project that so many alleged "electricians" suddenly find themselves unable to design a simple switching circuit for a load!?? [/SIZE]

[SIZE=10.5pt]Go back to basics a minute.....[/SIZE]

[SIZE=10.5pt]In essence an electrical circuit is just:-   [ Source of power ]->[ Switch or control device ]->[ Load ][/SIZE]

[SIZE=10.5pt]1) A source of power... {e.g. mains single phase / mains 3 phase / Transformer 12v / 24v / other / Battery / Generator etc.. etc..}[/SIZE]

[SIZE=10.5pt]2) A method of controlling the load... (e.g. manual switch or a switch controlled by; time of day / movement / daylight / temperature / gravity(position) / weight / depth  etc.. etc... ) [/SIZE]

[SIZE=10.5pt]2a) Some switches use lower power control circuits to switch higher power loads.. (e.g. relays contactors)[/SIZE]

[SIZE=10.5pt]2b) There may be more than once logical path to operate the load....[/SIZE]

[SIZE=10.5pt]switches wired in series or parallel can achieve logical 'AND' 'OR' functions.. [/SIZE]

[SIZE=10.5pt]change over switches or relays or contactors can be used to priorities one trigger path over another to provide exclusivity while one energising route is active..[/SIZE]

[SIZE=10.5pt]3) A load  that receives its power from one or more switching paths. [/SIZE]

[SIZE=10.5pt]Think what trigger routes do you need for your system..?? [/SIZE]

[SIZE=10.5pt]REMEMBER:-[/SIZE]

[SIZE=10.5pt]motorised valves have a small micro switch inside that is triggered when the motor has driven to the valve to the open position.[/SIZE]

[SIZE=10.5pt]As you don't want to be firing a boiler and running a pump into a closed pipe where the valve has not opened...[/SIZE]

[SIZE=10.5pt]Use the contacts on the valve to fire the boiler...  [/SIZE][SIZE=10.5pt]so you will only fire the boiler when at least one valve is opened![/SIZE]

[SIZE=10.5pt]Cylinder and room thermostats are just a temperature controlled changeover switch..[/SIZE]

[SIZE=10.5pt]With a Common / Norm Open / Norm Closed contact [/SIZE]

[SIZE=10.5pt]switches wired-in parallel can give a logical 'OR' function..[/SIZE]

[SIZE=10.5pt]switches wired in series can give a logical 'AND' function...[/SIZE]

[SIZE=10.5pt]So think WHAT do you actually want to do...[/SIZE]

[SIZE=10.5pt]Draw a simple block diagram of how you think it should work![/SIZE]

[SIZE=10.5pt]Then substitute the appropriate type of switch at each control stage.[/SIZE]

You need to understand WHY something is wired in a particular way not just which wires to join together...

As if it goes faulty 3months down the line you will NOT have a clue how to test or identify the problem if you cannot grasp how the system is supposed to be switching the load..

So there is not a lot of benefit from just having a list of join red to A, blue to C, black to B, grey to E etc.. etc..

Plus there are virtually NO standard colours for wiring between central heating controls..

you could find all sort of combinations and permutations..

SO you MUST understand the WHY and the HOW something is controlling the system.

[SIZE=10.5pt] :coffee  [/SIZE]