Boiler or Thermostat problem

Joined
13 Feb 2012
Messages
9
Reaction score
0
Location
London
Country
United Kingdom
Hi

I need help pls.

I have just replaced the mother in laws thermostat with a wireless one. A week before the boiler started playing up by coming on and going off. The system is pumped with 1 diverter valve.

Fitted the thermostat but the boiler is still playing up. She called british gas and the guy said the new thermostat was the problem because its not wired up correctly. He made this assumption without taking off the cover to see the wiring. The wiring from the electrical centre has a black, dark blue, green and red. The green is taped up and not connected.

The new wireless thermo has 2 lights, the 2nd light comes on when its calling for heat. The connections on the thermostat has L,N,1,2. I wired the red to L, dark blue to N, black to 2. Initially I wired the black to N but no lights came on. The thermostat lights work fine. The engineer told her that when the water starts to get hot it will turn the boiler off. Is this possible?

The wiring diagram for the thermostat shows the call for heat cable to be connected to 2.
 
Sponsored Links
It don't sound like a stat problem.

Is the 2nd light staying on when boiler firing up/shutting down ?
 
so the stat is constantly calling for heat.
Does this happen on heating or hot calling for heat or only heating ?
 
Sponsored Links
Is there a link wire in, else you need a live from the load and a switched live out.
 
Stat only calls for the heating. When the temperature setting on stat is turned down lower than the room temperature the 2nd light goes off like it should. I'm not a gas engineer but logically I cannot see its the stat causing the problem.
 
I'm guessing the red is a live and with neutral powers the lights and stats receiver. The instructions said that when both lights are on the terminal 1 makes a connection with terminal 2. Terminal 2 is the switch live wire.
 
Stat only calls for the heating. When the temperature setting on stat is turned down lower than the room temperature the 2nd light goes off like it should. I'm not a gas engineer but logically I cannot see its the stat causing the problem.

What i mean is when hw is on only does the boiler keep firing/cutting out in short intervals as you said it does with the heating ?
 
If the black wire in 2 is a switch live, what should the other end be connected to in the electrical centre. Is it common for 2 to be the switched line
 
Sorry I see. I havent tried it just with the hw on and heating off at the programmer. I have only tried it with both ch and hw on at the programmer
 
Its an ECO RF standard from toolstation. I guess I need to have a look and make notes on the wiring. Im 90% sure its a 3port valve. Does it sound like the stat and when the hw reaches a temperature shuts off the boiler.
 
The boiler will shut down with the boiler stat then when pumps circulated the water round boiler will fire up again.

But the way your saying it sounds like your boiler is cycling on/off every few seconds.

Or is that not the case ?
 
When stat calls after about 2 mins boiler fires up. After say 2 to 10 mins boiler goes off. Boiler then does the same cycle after anywhere from 2 to 20 minutes. When I tested it I made sure the stat was turned up to 25 and the room temperature was always lower than 20 degrees. I also checked that the 2 lights stayed on the stat the wireless sender was calling for heat. Its as if something is telling the boiler to turn off.
 
I thought your boiler was cycling say every few seconds.
A boiler will cycle on/off before room temp is reached from cold
It's turn off on the boiler stat untill the pump has removed the excess heat from boiler then fires up again and your room stat will be constantly calling

Whats the boiler stat set to ?
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top