central heating programmer

[chuckstre77]

I have a lifestyle LP241 programmer, which was recently knocked off the wall. It operates with a Potterton Housewarmer 55 back boiler. The programmer wiring was botched back together by a incompetent person (thats the least i will call him) I need to know what wiring goes where. Here is as it is now.

WIRING FROM BOILER TO PROGRAMMER
The SW live from boiler is going to terminal 3, the Live from boiler is going to L on programmer, and Neutral is going to N on programmer. There is also an earth wire - (see paragraph after MAINS)
PUMP TO PROGRAMMER
The 3 core from the pump - brown to Terminal 4 and blue to N. There is also an earth wire - (see paragraph after MAINS)
MAINS TO PROGRAMER
There is a 3 core wire going into programmer which i presume is the mains power as theres nothing else it could be.
2 of the 3 are connected (black to N & red to L) There is also an earth wire - (see next paragraph)
Now, thats the 7 wires that are connected to the programmer, there are 3 wires that arent connected they all appear to be Earth (green) which makes sense (1 from mains, 1 from boiler & 1 from pump).
Where ae each of the wires supposed to be?

 

[Taylortwocities]

There is a 3 core wire going into programmer which i presume is the mains power as theres nothing else it could be.

Don't you have a room thermostat??

 

[chuckstre77]

Sorry, should have stated. There is no room thermostat.

 

[ericmark]

I have a lifestyle LP241 programmer, which was recently knocked off the wall. It operates with a Potterton Housewarmer 55 back boiler. The programmer wiring was botched back together by a incompetent person (thats the least i will call him) I need to know what wiring goes where. Here is as it is now.

I googled the unit and first firm on the list http://www.heatingcontrolsonline.co...ys-lifestyle-lp241-24hr-programmer-p-105.html has a link to down load manual.

WIRING FROM BOILER TO PROGRAMMER
The SW live from boiler is going to terminal 3, the Live from boiler is going to L on programmer, and Neutral is going to N on programmer. There is also an earth wire - (see paragraph after MAINS)

PUMP TO PROGRAMMER
The 3 core from the pump - brown to Terminal 4 and blue to N. There is also an earth wire - (see paragraph after MAINS)

OK so far

MAINS TO PROGRAMER
There is a 3 core wire going into programmer which i presume is the mains power as theres nothing else it could be.
2 of the 3 are connected (black to N & red to L) There is also an earth wire - (see next paragraph)

Also OK

Now, thats the 7 wires that are connected to the programmer, there are 3 wires that arent connected they all appear to be Earth (green) which makes sense (1 from mains, 1 from boiler & 1 from pump).
Where ae each of the wires supposed to be?

Not sure where 7 wires come from you list 3 cables and that should be 9 wires if you are counting earths and 6 not counting earths.
This looks like a C plan as no motorised valve so both domestic and central heating need to run boiler but with central heating also the pump must run. With the setting to G you can’t have central heating without hot water so No 3 goes to boiler and No 4 goes to pump. If you want to have hot water off while central heating is running you need a motorised valve which will also have a set of switches which act as a relay then you can turn off the hot water.
If controller set to P instead of G it will not work.
Not sure what a back boiler really is. In my days it was a tank behind the fire and you had a damper to control if flue gasses went past the boiler or not but you could not turn it fully off so thermo siphon was used to heat domestic water so it could not overheat and when my mum had the fire roaring baking cakes the water would often boil.
I think the one your referring to is a gas job and is really a boiler hidden behind the fire and bar for using same flue they are really separate.
If you add a motorised valve to the supply to the cistern then you can add a thermostat to tank (I used radio one in my dad’s house) and so stop the water getting too hot.
I did some diagrams ages ago to help someone else see http://www.ericpalmer.fsnet.co.uk/Central Heating.html is may help you understand what you have.

 

[chuckstre77]

there are 10 wires in all, (the one from the boiler is 4 core) & the programmer is set to G. It is a potterton housewarmer back boiler. I just need to confirm which wires got to which terminal on the programer so it works correctly. eg....pump live to ?? pump neutral to ?? etc...

 

[ericmark]

All neutrals will go together.
I will guess from boiler you have earth, neutral, line permanent, and line run?
So line permanent will go with incoming line and other one with go to hot water out which as I said will be number 3.
The pump will connect to number 4.
Sorry I am not googleing for you have have given you link to controller.

 

[chuckstre77]

it seems that what you have just said, is exactly how it is currently wired - see original post. Could it be a faulty programmer?

 

[ericmark]

OK let me return to start. What is the fault.
All wires do seem correct.
You have not said what it is doing or not doing.
Back to basics you have a boiler and a pump.
Does the pump run when on central heating and stop when not?
Does the boiler fire up at any time.
What have you got to test with.
With my sisters house I as a temp measure replaced boiler with standard lamp then I could see what was happening as it is so easy for the boiler not to fire due to water too hot etc. And one can end up going around in circles.
Please remember I am an electrician not heating and ventilating and I know nothing about the boiler.

 

[chuckstre77]

I inherited a Potterton Housewarmer 55 when i bought my house that keeps locking out. It used to do this a while ago but stopped when i had it serviced. Since then, the father-in-law came to install us a wall unit, and knocked the programmer (Lifestyle LP241) off the wall. He rewired it (thought he knew what he was doing). I have had an electrician look at the wiring and he has now corrected, but he admitted he isnt an expert on central heating. There are 2 problems, when the heating is turned on, the boiler locks out after a while, and secondly when the programmer is not set (but boiler not locked out) it still ignites the boiler every few minutes until eventually locks out, but radiators don't get hot.

I have been told today in a plumbing forum that it sounds like the boiler is getting permanent live and short cycling untill overheat.

I have also been told that when the "$$$$er"-in-law attempted to rewire, he put a F1.6amp fuse in to replace a T1H (anti-surge) fuse as the one on the boiler control board blew during the rewiring. I am now thinking this may be the problem.

 

[ericmark]

The system you have described relies on the thermostat built into the boiler to switch boiler off when it reaches temperature. This was common with the older boilers.
It uses thermo siphon to heat hot water and often the flow is not good enough to sustain a constant burn.
There are two or more temperature devices in most boilers so if the main one fails there is a second to ensure it switches off but the second will not normally auto reset some manual intervention is required.
Assuming the pump is working and the boiler is smaller than radiators it may run constant when running central heating.
Because you can't stop it heating domestic water the only way to control the temperature of the domestic water is by setting the temperature of water leaving boiler there is normally a knob for this.
Too low and you risk legionnaires and too high and you burn yourself on hot water from tap. Also of course too low and central heating does not work very well.
Since you have a four core cable going to boiler I will guess you have some flue fan or the like which has to continue running even when boiler is switched off. If you have two live feeds wrong way around this could also cause a lock out.
I would say you have reached the stage to bite the bullet and get a proper heating and ventilating engineer to look at it.
It it is wired wrong so boiler can run without fan etc it could kill you. I would say not worth the risk.
With bad ventilation due to fan not running you are not only talking about CO2 but also CO which the blood will absorb before O2 and is a real killer.
Sorry to be so late with this but your original post did not give all the details.

 

[chuckstre77]

There is no fan, i have the installation booklet. The heating engineer is coming out tomorrow to remove the fire so the electrics can be looked at. Im going to get a LWC 3 Junction box to connect the mains, boiler & pump to, then connect to the programmer, i have the information booklet for the programmer now too. This makes should it idiot proof for the electrician that is hopefully coming tomorrow evening (he has been coming every day for a week). However, the instructions on connecting the junction box only show N, E & L coming from the boiler into the junction box. No mention of SWL. The wires are all sunk in to the wall and the 4 cores coming out of the boiler control panel all go directly to the programmer. None of the wiring on the control board of the boiler has been changed. Just the programmer end. Any ideas where the SWL will go to on the junction box?

PS, i am realy greatful for your input (and patience)

 

[ericmark]

Since you have people coming out better to leave it to them. I don't have book and would only be guessing

 

[chuckstre77]

Gas engineer has removed fire this morning if electricain cant sort the problem, then he will come back and have a look at boiler, but is pretty certain thats all ok. Electrician coming anytime soon to re-wire the lot, so with a bit of luck we will be nice and cosy and warm by tea time. I'll give you an update with any progress (if any).

Once again, thanks for your input and patience.

 

[chuckstre77]

Well, the electricians been and gone, rewired pump, mains & boiler to programmer. Still the same happening. After he scratched his head for a while, he blamed the boiler control board. It was definately NOT the programmer he said. When he had gone, i had an urge to remove the programmer, dismantle it and see if i could see any obvious signs of damage...........guess what?? There was more black than green on the board!!! There were at least 3 tracks burnt and loads of solder blackened as well as various melted spots. Now, im not saying that the boiler control board is working 100% perfect but i thought the cheapest option was to go and buy a new controller. I went to B&Q, bought a sunvic 207 xls as the wiring is the same. Got it home, took it out of the packaging and found that it was a used programmer that was broken, obvious signs include pen mark on the reset button, the link wire cut. Now, B&Q is closed until tomorrow. If i werent so pi??ed off with the whole situation, i would laugh. I will go and exchange it tomorrow cos im sure it must be what has caused the whole problem (surely), just thought i would give an update and hopefully make you smile!!