Central heating timer!!!

[jdmgriffin]

Hi there. Ok so came back to no display on the timer! Couldn't see anything blown. So isolated to switch. Took off the unit an salus ep100 and found the first image attached!!!!

I disconnected the unit and found the fuse in the isolating switch must have tripped it out. Power goes to this unit when I power it up.

Ok so issue is can anyone tell me what went wrong!!
And can I put in just s regular timer for my heating now. It's not zoned at this point and is just straight wires out to the boiler.

The only thing I can think of is that....there is a feed that comes from the boiler to a small shed which houses the washing machine....the washing machine would have been on when the timer kicked it....it had been previously like this for quiet a whole with no issue.....




In the interim is there a way just to use the isolating switch to turn on the boiler ? Use it as the on/off switch per say......

 

[Terrywookfit]

This has got to be a wind up !!

 

[ericmark]

It would seem an overload on neutral, think unlikely a correctly wired timer would have anything like the load on the neutral to cause that even with a lose connection. So it seems likely some error, most units using that plate fused to 3 amp or at least rated 3A and although not impossible with a loose connection to cause that damage, it raises the question where does that outgoing neutral feed?

Borrowed neutrals are very dangerous, and it seems likely you have a borrowed neutral.

 

[jdmgriffin]

Hi and thanks for the reply. It does appear to be borrowed.
I followed this wiring.
So we have from the breaker a
Three core into a 13amp isolated switch.
This then feeds into the timer for the boiler, which is now needing replacing.
From this
There is a five core cable going to the boiler and being then split to have the three earth, live, neutral feeding to the boiler itself/pump.
The other two wires black and grey were being used to feed a three core to the shed we have.
These black and grey were being fed from the timer box connections.
Could you tell me how this should have been done so we can ensure our electrician does it correct.

 

[lostinthelight]

Doesn't sound like your man's an electrician if you don't trust them to do it right

 

[Terrywookfit]

It would seem an overload on neutral, think unlikely a correctly wired timer would have anything like the load on the neutral to cause that even with a lose connection. So it seems likely some error, most units using that plate fused to 3 amp or at least rated 3A and although not impossible with a loose connection to cause that damage, it raises the question where does that outgoing neutral feed?

Borrowed neutrals are very dangerous, and it seems likely you have a borrowed neutral.

The blue wire to T1 is a live...Water off used on Y plan and Mo Mo.

 

[ericmark]

The blue wire to T1 is a live...Water off used on Y plan and Mo Mo.

Unreadable due to melting then L 1 2 3 4 it seems reasonable to assume melted wire is a neutral.

If using a Y plan then yes can get a diagram, but we don't know how it is wired, in general people follow the honeywell plans, Y, S, C, W etc. But some have been modified through the ages, specially the C plan.

So to start with the boilers, well really water heaters we don't want it to boil the water, but we will call them boilers, we have the system boiler where all controls are outside of the boiler, and the combi boiler where the domestic hot water (DHW) is all controlled internal in the boiler. We also have boilers that simply switch on/off, and boilers that turn up/down (modulating) I would guess you have on/off system boiler, these also split into two those simply switched on/off and those with a cooling cycle. With the latter normally power goes to boiler first and then to the controls. So the boilers one normally look at have a earth (E), neutral (N), permanent line (L) and switched line (SL) and power goes to boiler first.

To switch between DHW and central heating (CH) there are many methods, simply switch boiler and pump for central heating and boiler only for DHW is one method, but in the main we like to add thermostats, either for room temperature or DHW temperature although latter some times only works in the summer. But the more modern system uses motorised valves. What is normally done is the thermostat works the valve and the valve works the boiler.

We have two port valves normally used with S plan, and three port normally used with Y and W plan, W plan has a small tank and Y plan a large tank, there are variations with zone and DHW motorised valve with C plan, but job one is work out what system you have. So pictures are good specially of any valves or tanks. Boiler make and type will also help, but I am sure there are books on how to wire central heating so step one narrow the field.

 

[Terrywookfit]

Fook me ...It's professor Google !!?

 

[jdmgriffin]

Thanks for your replies on this.

Ok we have said we would look at the controls on a whole to see if we can get it all running a bit more efficiently.

Our setup / equipment we have is.

Upstairs hotpress...
Sealed system.
Dual immersion on dual switch bath/sink
Upstairs with two way port on single switch
Downstairs with two way port on single switch

Downstairs
Isolated switch connected to a timer (now needing replacing)
Five core (e,l,n,BLK,gry) wire from bk of timer to boiler
Boiler is a c26 condenser boiler oil fired.
https://www.plumbingproducts.ie/out...max-heatpack-slim-c26-condensing-boiler-.html
With a grndfos alpha pump
https://ie.grundfos.com/products/find-product/alpha2-l.html

What we would like to do is be able to control hotwater seperately (at the minute the switches for the valves to shut off upstairs and downstairs are up at the hotpress) and the timer is downstairs that goes to the boiler.

Thanks again for your replies.
I'm figuring a timer downstairs and manually turning on off the valves upstairs is our best option at the min. But open to looking at reconfiguring if it works better.

The house is well insulated so holds heat well.
We have just put in a integrated stove so that will pretty much heat downstairs when we have it on.
So it's just really the hot water during the summer and a bit every few evenings for the rads.
Wife had read online about leaving dual immersion on constant on to keep hot water hot....more efficient ?!?

 

[Terrywookfit]

Fit a 2 port valve in Cylinder ( Hotpress) ?? pipework and wire as Honeywell Splan Plus !!

Simples!!

 

[Terrywookfit]

Leaving Immersion Htr on constant will cost a fortune and burn it out very quickly.