wiring diagram

[maccarooni]

Been asked to look at a heating system thats not working. The plumber (whom I have never met before) gave the customer my number. Anyhow the the system is fully pumped. potterton boiler. cylinder plus stat. Room stat. programmer. 2 pumps and this is the bit I've never come across before. Backboiler plus stat on the heat exchanger. apparently when they light the fire, it shuts off the boiler. Is there a wiring diagram available for this kind of system? I would like to go armed with some info about the setup as I think someone may have been tinkering..........

Macca

 

[Lurch]

You don;t really need a diagram, treat it as 2 systems. The first system is the conventional bit, the pump, valve (s, if any),cylinder stat, room stat and programmer. Onto the side of this there is an additional pump for the back boiler and a stat. I would imagine the pipe stat will cut the boiler feed and fire the second pump up when it gets warm.

There isn;t really a name for the system so you can;t really have a diagram anyway, there's a few ways of doing it and it's not entirely a standard set up. The main thing to look at is the pipe stat and second pump, once you've got that sussed the rest is straight forward.

 

[maccarooni]

Thanks lurch, So I take it that once original setup is functioning correctly, a three core cable to the stat on the exchange stat, common to N/C to allow feed to boiler, N/O contact would have return to pump, when rise of temp is ackknowledged by stat.it switches power from boiler to pump?. Does that sound about right.

Macca

 

[Lurch]

Something like that. It depends on the design of the back boiler water circuit as well as it may need to fire up the pump regardless of the heating controls status due to the possibility of the heat exchanger exploding. I've done a few of these sorts of things and I think every one has been different, some work, some don;t, some have relays, some don;t etc...

 

[maccarooni]

From what the customer has told me ( not that its always entirely correct ) it has been working for about five years since it was put in. last spring it stopped working and they had someone out who changed something in the boiler its still not working and a different plumber ( who gave them my number ) told them it was an ecletrical problem. I will be popping up to have a look at it Wed/Thur. so will see whats what.

Macca

 

[m4tty]

Let us know how you get on mate. Sounds interesting

 

[maccarooni]

TBH matty,

Sounds like a headache as its been passed around. Dont know what the others have done with it. will report back accordingly.

Macca

 

[maccarooni]

OK

Been to look at it today and its a mess.

There has been 2 sparks there before me, 3 plumbers, has been well and truly tinkereed with.

Now info I know

Feed for system in kitchen beside programmer and boiler

1. danfoss fp715 programmer in kitchen

2. Potterton boiler lpg 50e L-N-E-SwL in kitchen

3. hot water tank with sunvic sz6355 actuator in loft

4. cylinder stat on tank in loft.

5. 2 x pumps in loft

6. heat exchange in loft.

7. 2 x anti boil stats fitted to exchange.

8. one hell of a messy control terminal box in loft.

Now the antiboil control system works like this. In the event of an overheat situation anti boil stat number 2 which in this case is on the LHS of the exchange is set at 85 degrees C will MAKE and and switch on the space heating pump.

If the space heating pump or electricity should fail, antiboil stat 1 on RHS of the exchange set at ?? (cant read the temp on paperwork, but stat was on 45 degrees C )will break and allow spring open motorised valve to open. this will switch off the gas fired boiler and open the cylinder circuit.

Now based on thi information I have drawn up a wiring diagram and would Like all you cahps to have a look at it and tell me if it will work and if not pointers as to where my mistakes are.....

Yours under pressure

Macca

........................ :Blushing ............................

 

[Lurch]

Erm, yeah.

First thing I noticed, the only thing connected to the boiler switch wire is the DHW off on the clock. Are there some links missing?

For anything else, I need to look at that when I'm slightly more awake and the thinners has evaporated from my head a bit.

 

[maccarooni]

Thanks for that Lurch,

managed to track the Co. who supplied the heat exchange, which is actually called a neutralizer and the co is called Dunsley heat ltd. up in Yorkshire, I believe.

The tec guy has faxed me across a wiring diagram and is also posting one. ( hows that for customer care 10/10). I will upload it as soon as the kids are ferried in/ out etc etc. its friday club night/swimming/something else.........

Macca

 

[maccarooni]

Ok heres diagam from the company, some confusion still as theres 2 pumps in the loft and I'm presuming one is the boiler pump, so how do i know which one is which.would the boiler pump be fitted on the outgoing flow pipe? any way comments please The boiler is a potterton 50e lpg.

Macca