Triton 7KW shower - is it a load or carp or what?

Discussion in 'Plumbers' Talk' started by Cornish Crofter, Nov 22, 2005.

  1. Cornish Crofter

    Cornish Crofter Active Member

    I recently fitted a Triton 7KW shower for a client.

    She came around tonight to pay the bill, and told me that she doesn't like the shower. As she's paid the bill she's IMO not looking for an excuse not to pay it.

    Now I did warn her that it would not be as powerful as the 8.5kw mira that had to come out (knackered). However when it's cold the pressure is OK, but when you get it up to a reasonable temperature the pressure drops to that you'd expect from around 1/2 a metre of head - **** basically.

    Now it reaches quite a high temp when you turn it up to around 5 (scale 1 to 10).

    I'm thinking either;

    -Blockage
    -7KW is pathetic compared to higher rated models, and that's what I should expect.
    -Problem with the shower unit itself.

    Tomorrow I'm going to check the filter to see if it's blocked. The water authority have been digging up the roads around and about recently, and I've had to unblock someone else ballvalve (didn't charge them for it).

    If this does not improve matters, then I'm stuck with a shower that is either pants anyway or is not working properly.

    Either way, then I risk a charge from Triton if they can't find a fault, if I call them out, which then puts me into loss territory for that job.

    Any advice on what to do after I've checked for blockages. I think this is one of those jobs I wish I'd never taken on :(

    Thanks

    CC
     
  2. Londoner

    Londoner Member

    Not certain about the Triton, but generally, these showers control temperature by adjusting the flow over a fixed capacity heater (7kw in your case). If "pressure" (flow) is OK on cold setting (even if head is as low as you say), then unlikely to be a restriction in supply (as same single water feed). 7 kw really is very borderline for a decent shower, particularly in the winter months when the water supply temperature is so much colder). I've got one in our home and wife won't use it for this reason (fortunatelly, I've got a standard mixer shower too, so soves my problem but do plan uprating the electric one some time). I'm curious though, why did you go for the 7kw unit to replace the superior 8.5 kw one?
     
  3. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Did you commission the shower correctly(forgive any sucking eggs hints) ? ie with the shower head removed.

    I would check the shower rose for contamination first, as from your description, the pressure/flow is there when cold and the water is hot when flow is reduced.

    Are you with me ?

    Sounds like the water is getting in well enough but staying in too long because the shower head is restricting it at low pressure.




    Mr. Handyandy - really
     
  4. Cornish Crofter

    Cornish Crofter Active Member

    Many thanks for those who replied so far :)

    Londoner, to answer your question about why I replaced an 8.5KW shower with a 7KW - The client wanted to save money, so was keen on spending less for a 7KW despite my informing her that the performance would be inferior.

    Also, The MCB at the CU was only 30Amps. Technically, putting in a new 8.5KW would have provided the potential of nuicance tripping as it would have meant needing about 36A protection, thereby giving the customer just cause for complaint, forcing me to change the CU set up and do a complete Inspection and Test cert for that circuit, at my cost. Having said that the old 8.5 didn't do this which I put down to its condition (poss high resistances), but I couln't guarantee the new one wouldn't

    Hence, after discussing the risk of nuicance tripping with the client (and money was a factor), she decided to go for the 7.0KW. However I did warn her that the performance was likely to be inferior and she appeared to take this on board.

    Mr Handy Andy - teaching me to suck eggs? no not at all I'm grateful for your help. I checked the shower head, and ran it through with the shower rose connected and disconnected. I shall do this again before I check the in line filter for debris. The client asked me to connect it up to her old shower head, which is a Mira one and has an area of around a 3rd greater that the new triton - maybe this is a clue...

    According to Triton, The setting should be on 7 or 8 at this time of year to reach a reasonable temp, whereas I have it on 5 with a reduced flow, which leads me to think that it could cope with more pressure.

    Oddly enough, to support what has been said about these showers by british blue on the other thread, I fitted an identical unit in a house not far from this client. This too seems low on pressure when heat is applied..... Originally I fitted this shower in the summer it behaved fine.

    I suppose as has been said, the temperature of the incoming water plays a huge part.

    I'll report back.

    CC
     
  5. Cornish Crofter

    Cornish Crofter Active Member

    An update.

    I contacted Triton who gave me some data to check the shower against.

    Flow rate for cold/max flow between 6 and 8 Litres per min.

    Flow rate for hottest/min flow between 1.8 and 2 Litres per min.

    I checked this using a measureing jug - results as follows:

    Max flow rate was around 7 litres per min
    Min flow rate was 2 litres per min.

    So I informed the client that the shower was working properly, and that the lack of performance was due to a combination of cold weather and the limitations of the shower.

    She seems OK with this, especially taking into account that a higher rated shower will cost a lot in terms of the CU upgrade.

    Thanks again for all the help and guidance.

    CC
     
  6. Londoner

    Londoner Member

    As you are finding out, you can just about get away with 7kw in the summer (with a fine rose), but flow rate for warm water really is too low in the winter. 8.5 kw does seem to make a lot of difference (and the 10.5 kw showers even better). You say protection is via a 30 amp MCB (not 32 amp?). Either way, fuse or MCB, have a look at your BS7671 fuse and MCB curves and I suggest that you'll see why they don't trip. Fuse blow or MCB trip times at 36 amp's are a lot longer than the average shower time (in fact, longer than several consecutive showers). I've seen other 8.5 kw showers on both 30 amp fuses and 32 amp mcb's and they don't trip for the same reason.
     
  7. Cornish Crofter

    Cornish Crofter Active Member

    That's a fair comment Londoner.

    However, if faced with a shower that kept tripping the MCB after I had fitted it (assuming I was that unlucky), then the customer would have had every right to be upset with me. I appreciate that the likelihood of that happening is low. Besides would we not have a situation that is against the spirit of the regs?

    In addition, fitting it in this way would have contravined the advice of the shower manufacturer and may have complicated matters for the warranty if she ever needed it.

    Having said that you've made a good point - worth thinking about for another time.....
     

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