is this acceptable??

[pmac10]

i'm not a domestic spark or a plumber for that matter, but my da phoned the other day to say my granny had no hot water function from her boiler, dual programmer and the heating was working fine. traced the fault to a two port motorised valve with aux. contacts not working and to pull her out of a hole i opened the valve manually and linked the 'valve open' signal to bypass the N/O contact so the burner would fire.
anyway, went back today to make the job right with new valve and found this electrical system is on a lighting circuit? (the last fuse i pulled). i did 16th edition in 2007 and dont remember much about it but is this acceptable practice???
any opinions lads?

 

[xraytek]

What exactly was the valve you bypassed
It might be remaining closed for a reason i.e. flue blocked or some safety issue like that.

 

[pmac10]

it allows hot water from the boiler to be pumped to the hot water tank, dont panic mate, im an industrial maintenance engineer and work with these systems in a factory day to day, just pretty sure lighting circuits are for lights, is it acceptable to tap off these?? got my alarm bells ringing.

 

[philip962]

Doesn't sound right heating should be a fused spur off a ring or radial that's what I would do anyway.

 

[pmac10]

Doesn't sound right heating should be a fused spur off a ring or radial that's what I would do anyway.

thats what i thought and thats what i would have done, this is an ex housing executive dwelling which my da bought for his mum and shes the only one to have lived in it so this is housing executive sparks handy work.
cant think of any danger though as its all on a 5A fuse or is there?

 

[Spudnik]

I dont think there is any danger, however, it is probably pushing the limits on the circuit capacity, especially if there many lights.

 

[Guest123]

As said apart from a loading issue then I can't think of a reg as such against such an arrangement, providing the OCPD for the associated lighting circuit hasn't been upgraded to cope and is now over the CCC of the circuit cableing. As you say it's on a 5A then protection is within limits.

Bad practice....yes, a danger...no.

 

[pmac10]

thanks lads, as an afterthought, was gonna carryout this job with the controller off but remembered a story from an instructor on an OFTEC course i attended. it was 1625 on friday afternoon and the guy was due to knock-off at 1630. so he just turned the controller off. kids came home from school at 1630, mum and dad got home from work at 1630, and guess what, the heating was programmed to come on at 1630! BANG!
no serious injuries but got me thinking and a lesson learned...............