Smell of rubber

[ro63rto]

Bought a house with old bathroom. Changed old Triton t80 7.5kw with Triton t80si 8.5kw as the guy said the wiring was of the right gauge to take it. Started using the second step in the power (not heat) setting and I started smellimg a rubber smell around the house. Never put two and two together til this morning when I went to turn off the shower fuse. The fixture was quite hot.

Was he BS'ing me in saying the wire was ok or is ther another reason for the smell?

 

[ban-all-sheds]

What size is the cable, where does it run, and how long is it?

What type and rating is the protective device?

Who was the guy who gave you advice?

Did he inspect the wiring before telling you it was OK?

Did he test the circuit before telling you it was OK?

Did he tell you it was OK on the basis of information you provided him?

What did you tell him?

Did you test the circuit before you fitted the shower?


Things getting hot, and smells of burning are OK with barbeques, less so with electrics. If you don't have the skills to investigate and fix this pronto, you should get an electrician in. Should be OK - I doubt he'll shop you to LABC...

 

[andy]

Bought a house with old bathroom. Changed old Triton t80 7.5kw with Triton t80si 8.5kw as the guy said the wiring was of the right gauge to take it. Started using the second step in the power (not heat) setting and I started smellimg a rubber smell around the house. Never put two and two together til this morning when I went to turn off the shower fuse. The fixture was quite hot.

Was he BS'ing me in saying the wire was ok or is ther another reason for the smell?

i take it as whoever told you wasnt an electrician

 

[ro63rto]

Guy who told me it would be ok was the one i bought it from. He said if wiring had been fine for 7.5k it would be ok for 8.5k.

Problem is I don't think the guy that did the bathroom put wiring in conduit of any sort. When he pulled off the old shower, that wire was just buried in the plaster.

I may have to stop using the shower as I don't have the funds to destroy half a wall/tiles and remove the bath etc to re run the cable.

 

[andy]

Guy who told me it would be ok was the one i bought it from. He said if wiring had been fine for 7.5k it would be ok for 8.5k.

Problem is I don't think the guy that did the bathroom put wiring in conduit of any sort. When he pulled off the old shower, that wire was just buried in the plaster.

I may have to stop using the shower as I don't have the funds to destroy half a wall/tiles and remove the bath etc to re run the cable.

just because it can take 7.5KW doesnt mean it can take 8.5KW. my guess is you have 4mm in. you should have a minimum of 6mm. or go further and use 10mm so when you decide to go for 10KW you dont have to go thru all this again

 

[plugwash]

you were given some very bad advice then you should NEVER uprate something like a shower without checking out the size and installation method of the existing wiring.

 

[Spark123]

What size fuse? Is it a fuse or MCB? It could be this getting hot due to overloading. I agree with plugwash, you should have an electrician come and check your wiring to see if it is capable of taking the extra current of the larger shower.

 

[ro63rto]

B4 work yesterday I switched off the main switch for the shower downstairs. Got home last night and took a look at the fuse.

Spark123, you were right. Is a 30A cylindrical fuse in a plastic holder. My God, my house could have burnt dowm. It was this that was giving off the smell.

The cable is 10mm wide. How do you measure gauge?

All other "fuses" on the CU are of the quick blow resettable type but NOT the shower one. By my calcs I need 40A.

 

[Adam_151]

Cables are measured by the surface area of the conductor, this might be stamped on the outer jacket of the cable, otherwise its difficult to tell, usually after a while people get a 'feel' for cable sizes and can tell by eye.

1mm² CSA T&E has overall dimensions of 7.8mm x 4.25mm
1.5mm² CSA T&E has overall dimensions of 8.2mm x 5mm
2.5mm² CSA T&E has overall dimensions of 10.3mm x 6mm
4mm² CSA T&E has overall dimensions of 11.9mm x 6.25mm
6mm² CSA T&E has overall dimensions of 13.5mm x 7mm
10mm² CSAT&E has overall dimensions of 17.1mm x 10mm
16mm² CSA T&E has overall dimensions of 19.4mm x 10mm

Source: http://www.tlc-direct.co.uk

 

[ban-all-sheds]

My God, my house could have burnt dowm.

Yes, but because of cable overloading, not the fuse. Fuses are designed to carry a certain current safely, and to rupture in a given amount of time depending on the extent of the overload - it ought not to be possible for any current to cause the fuse to catch fire. Loose connections where the cables screw in, or a poor grip on the fuse itself can cause overheating though.

It was this that was giving off the smell.

More likely to be one of the other causes I mentioned, or just the cable getting too hot - have a look at the isolation switch in the bathroom and see if there is any sign of overheating.

The cable is 10mm wide. How do you measure gauge?

Surely it can't be 2.5mm²?

Can you see if either the L/N conductors are stranded rather than solid, and ditto for the earth one?

All other "fuses" on the CU are of the quick blow resettable type but NOT the shower one. By my calcs I need 40A.

Please do not simply replace it with a bigger one, as the cable you have is almost certainly undersized.

See here: //www.diynot.com/forums/viewtopic.php?p=81696#81696 for an explanation of the relationships between load, fuse and cable ratings.

 

[ro63rto]

thanks for all the info guys.

2x4 time to the guy that installed the bathroom.

Now I will have to break the wall tiles, remove the bath and screen, break the floor tile (damn expensive ones from Italy and run a new cable as I BET he did NOT use any sort of conduit inside the wall where I could just pull the new cable through!

Guess that's what you get from not wanting to pay 3 grand to fit it....

This is something I cannot afford as the roof is leaking. Will probable have to dsconnect shower and stick to baths for a while.

 

[ban-all-sheds]

Can you install a new cable that gets up into the loft, and then comes down the wall to the shower?

 

[ro63rto]

Can you install a new cable that gets up into the loft, and then comes down the wall to the shower?

Not easily. CU is under open staircase.

Would you mean coming down through some sort of waterproof conduit or still break tiles?

 

[ban-all-sheds]

You could use conduit, if you can be sure of getting it watertight, but putting it under the tiles would be better. A lot fewer to replace if you come down from above.

Also, if there is enough vertical clearance in the loft you might be able to drill down through the wall to a point behind the shower housing, although this would be tricky.

 

[ro63rto]

You could use conduit, if you can be sure of getting it watertight, but putting it under the tiles would be better. A lot fewer to replace if you come down from above.

Also, if there is enough vertical clearance in the loft you might be able to drill down through the wall to a point behind the shower housing, although this would be tricky.

Only two tiles above shower so this would be the better option.

Just have to figure out the route for the initial run up into the loft first.

Q. If the previous shower (a manky looking 7.5k Triton) was used for 9 years on same cable and same 30A fuse, surely that should have caused some problems for the previous owner?