Mains wire to boiler timer overheating

vikramrkin

Hi All,

I am looking for some help with my boiler timer. I have 10 year old Pulsacoil A class boiler. The existing TimeGuard timer had stopped working so I replaced with a newer model of TimeGuard (NTT08). In few weeks I noticed that the timer and the mains lead going into it were so hot that the wire had become sticky to touch. I contacted the seller who sent me a replacement unit. Now even the replacement unit has the same problem.

I am wondering if there is something wrong with my wiring or worse boiler?? TimeGuard did say that I should be using a 2.5mm lead. It looks that thickness and it is the original electric wire fitted when the house was built. So I assume they would have used the correct thickness?

Any help will be greatly appreciated.

Thanks
Vik

Aylesbury_Duck

Dangerous assumption. Get a professional to check the wiring to make sure it is the correct rating for the use. "It looks thick enough" isn't really a safe way to assess it.

vikramrkin

Aylesbury_Duck wrote: »

Dangerous assumption. Get a professional to check the wiring to make sure it is the correct rating for the use. "It looks thick enough" isn't really a safe way to assess it.

Thanks for the reply. The timer is switched off and I am using the boiler with "On peak boost" button which bypasses the timer.

I wanted to ensure that it is not a timer device problem before calling an electrician.

Thanks
Vik

Aylesbury_Duck

I suspect that the timer is fine. It would be an unfortunate coincidence if both units were faulty.

Moss5

http://www.pulsacoil-repairs.co.uk/pulsacoil-A-Class.html

Looks like you have a defect that is known about.

molerat

Why did the original timer stop working ? Overheating maybe ?

The above linked fault is an on unit wiring fault but as it is overheating on the off peak side could be the root cause of your problem. Get someone in to have a look if you are not confident enough to take the front off and look for burnt wiring inside. Looking at the wiring diagram only 1.5mm flex is required to feed the unit so if 2.5mm is overheating you have a problem. http://www.gledhill-response.net/wp-content/uploads/2016/06/PulsaCoilAClass-Iss9.pdf

Strider590

vikramrkin wrote: »

TimeGuard did say that I should be using a 2.5mm lead. It looks that thickness

It's not thickness, it's cross sectional area. 2.5mm2 is quite a thick wire.

Despite this, I think something else is afoot, maybe something not wired correctly.

vikramrkin

Thanks for all the replies. I think I will get a professional as I don't want to mess with the boiler!

MonsieurFrugal

Id check all the connections are tight. Most electrical fires start because there are loose connections

ohreally

2.5 is a heavy conductor and I'm not sure it would fit the terminals.

vikramrkin

ohreally wrote: »

2.5 is a heavy conductor and I'm not sure it would fit the terminals.

Not sure, that's what time guard told me. Anyways, have booked an engineers visit this weekend so hopefully the problem is fixed!