Crofter Posted November 22, 2016 Share Posted November 22, 2016 Our (current) house is all electric, on the 'Total Control' system. This means that we have two rates, one for space and water heating, and one for everything else. Currently we heat DHW using an electric immersion, but this is horribly inefficient as the small tank sits in a cold loft space and loses heat quickly. It also leads go a rather unpleasant showering experience. With SWMBO's words ringing in my ears ('dearest sweetheart, might you perchance be able to put your mind towards installing an electric shower, just when you get the chance.'- OK I'm paraphrasing as her actual words are not printable) I would like to install a basic electric shower. Question is- can I just buy a big enough breaker and stick in the existing CU? In our previous house there was a mini CU especially for the shower. I know these aren't that expensive but just wondering if it's needed or not? Link to comment Share on other sites More sharing options...
SteamyTea Posted November 22, 2016 Share Posted November 22, 2016 48 minutes ago, Crofter said: It also leads go a rather unpleasant showering experience. So could the alternative if it is not sized right and your water pressure is not good/consistent enough. I can't think of any reason why you cannot change the breaker. You will need an RCD (or an RCBO) as it is shower. What power shower where you thinking of fitting? Link to comment Share on other sites More sharing options...
Crofter Posted November 22, 2016 Author Share Posted November 22, 2016 Even a rubbish little electric shower will be better than what we have, believe me. Water pressure is excellent. Was assuming around 9kW, but whatever the supply allows me to do, Link to comment Share on other sites More sharing options...
SteamyTea Posted November 22, 2016 Share Posted November 22, 2016 Have you thought of fitting one of these: http://www.anchorpumps.com/new-stuart-turner-techflo-tp-s1-5-bar-twin-positive-standard-shower-pump-whisper-quiet-range-240v-49084?gclid=CIrV98muvNACFQ5mGwodfQcAhA Similar to what I have hanging off my UVC and Header tank. Does not help you with the heat losses from the small cylinder though. Link to comment Share on other sites More sharing options...
Temp Posted November 22, 2016 Share Posted November 22, 2016 Can you expand a bit on what you mean by "a rather unpleasant showering experience"? When you say the pressure is good do you mean the mains pressure is good but the shower pressure is low? If so that sounds like the tank in the loft is a vented tank. Switching to a well insulated mains pressure tank might be an option. Link to comment Share on other sites More sharing options...
Crofter Posted November 22, 2016 Author Share Posted November 22, 2016 So the problems are threefold: - extortionate electricity bills (have had £500 for a quarter before, this is for two misers in a 90m2 house who use a woodburner as much as possible and do not expect to wander around in shorts and t shirts in the middle of winter. The water heater is the culprit, as when I have got away with turning it off and just boosting the water an hour before it was needed, the bill dropped hugely. I'm not allowed to do that anymore for, uh, domestic reasons, so the system stays on all the time. - poor flow rate and pressure at the shower. It's a gravity fed TMS coming from a loft header tank and vented cylinder. Exactly the same setup as I installed on my previous house (except that was oil fired) and the only difference is the make of shower. The previous house installation, with a Mira, was perfectly acceptable. This house has, if anything, more head, but some cheap unbranded TMS. I've switched to full bore valves on the pipes which helped a little, but still very poor. - insufficient quantity of hot water. We have the thermostat on the tank turned as low as we dare, to keep the bills down, and now that the weather is turning colder we find it is running out of hot water before the end of a single shower. And this is despite the poor flow rate of the shower itself. I'm sure there are lots of all singing all dancing solutions to this, UVCs and whatnot, but I have decided that spending a weekend and £150 installing an electric shower will let me turn the damn tank off and will give lower bills, more consistent showering, and probably a better flow rate. Even as a temporary solution it has to be worth a try. All my energy needs to be focused on the other house (the new build) so I am not getting bogged down improving this one at this stage. Remember I have 24/7 access to cheap rate electricity so there is not need for me to be paying for standing losses. Anyway, I wasn't really after a discussion on all the various options, just the specifics of installing a leccy shower. Link to comment Share on other sites More sharing options...
Steptoe Posted November 22, 2016 Share Posted November 22, 2016 An RCBO isn't the best option, as for a wylex board they are only single pole, best fit an MCB and an external RCD, Are the main earth bonds in place,? 10mm? Link to comment Share on other sites More sharing options...
Crofter Posted November 22, 2016 Author Share Posted November 22, 2016 34 minutes ago, Steptoe said: An RCBO isn't the best option, as for a wylex board they are only single pole, best fit an MCB and an external RCD, Are the main earth bonds in place,? 10mm? Erm, I may need some of this translated What do you reckon I need to buy, and is it expensive? Will probably get the sparky up the road to do the job (legal requirement anyway for this sort of job, no?) but as this is potentially only a temporary setup don't want to be forking out too much... Link to comment Share on other sites More sharing options...
SteamyTea Posted November 22, 2016 Share Posted November 22, 2016 I have separate MCB and RCD units fitted on outside of bathroom wall. I seem to remember they were about 40 quid. Then you will need a large cable to the shower unit and probably some trunking to hide it. Link to comment Share on other sites More sharing options...
Onoff Posted November 22, 2016 Share Posted November 22, 2016 Parts won't be much if you fit something like this. I'm not saying this but it'll give you an idea: http://www.toolstation.com/shop/Electrical/d190/MK+Consumer+Units/sd3134/MK+Shower+Consumer+Unit+IP65/p80581 You need to consider the chosen shower's load, cable length and how it's routed to gauge the cable size required, isolation switch position etc. BUT this really is one where you don't want to be doing it yourself. Leccy + water + kids etc. One of the biggest loads in a house. Link to comment Share on other sites More sharing options...
ProDave Posted November 22, 2016 Share Posted November 22, 2016 What nobody has picked up yet, is you have "total control" a Tariff I believe unique to Scotland and no longer available to new customers. It's a bit like Economy 10 in that the the storage heaters and the whole house gets cheap rate for 10 hours a day. BUT it has one BIG advantage that the "A circuits" are always on, and always metered at the cheap rate. These are supposed to only be used for "heating appliances" and typically you will find panel heaters in bedrooms connected here. But you are also allowed to connect water heaters and Showers. So all you need is a wylex 40A rcbo and you can have cheap rate showering 24/7. You lucky b%%$$"£$£$£ 2 Link to comment Share on other sites More sharing options...
Crofter Posted November 22, 2016 Author Share Posted November 22, 2016 Thanks, Dave. Something like this? http://www.toolstation.com/shop/p14865?utm_source=googleshopping&utm_medium=feed&utm_campaign=googleshoppingfeed&mkwid=s3Z3fpJI3_dt&pcrid=99808204703&pkw=&pmt=&product=14865&gclid=CPaSkKXtvNACFcsV0wodTSQMUg Link to comment Share on other sites More sharing options...
Onoff Posted November 22, 2016 Share Posted November 22, 2016 If he's on TT wouldn't DP protection be better? Link to comment Share on other sites More sharing options...
ProDave Posted November 22, 2016 Share Posted November 22, 2016 Is he on a TT supply? Agree with Steptoe, a 40A mcb in the CU and a 2 pole 2 module rcd in a separate enclosure would be better. Link to comment Share on other sites More sharing options...
Crofter Posted November 22, 2016 Author Share Posted November 22, 2016 What's a TT supply? Link to comment Share on other sites More sharing options...
SteamyTea Posted November 22, 2016 Share Posted November 22, 2016 Terra Terra Earthing, basically a large nail in the ground Link to comment Share on other sites More sharing options...
Onoff Posted November 22, 2016 Share Posted November 22, 2016 40 minutes ago, Crofter said: What's a TT supply? Sorry, we're interested in your earthing system as it can impact on the new circuit. Likely to be one of 3 types. Rather than go in to chapter and verse and on the basis a picture says a thousand words you have a pm 1 Link to comment Share on other sites More sharing options...
Stones Posted November 22, 2016 Share Posted November 22, 2016 3 hours ago, ProDave said: What nobody has picked up yet, is you have "total control" a Tariff I believe unique to Scotland and no longer available to new customers. It's a bit like Economy 10 in that the the storage heaters and the whole house gets cheap rate for 10 hours a day. BUT it has one BIG advantage that the "A circuits" are always on, and always metered at the cheap rate. These are supposed to only be used for "heating appliances" and typically you will find panel heaters in bedrooms connected here. But you are also allowed to connect water heaters and Showers. So all you need is a wylex 40A rcbo and you can have cheap rate showering 24/7. You lucky b%%$$"£$£$£ I wouldn't describe THTC as cheap by any means - we have it in the house we are currently renting: Heating control 9.34p / kWh, Standard energy 18.5p / kWh, Standing charge 14.09p per day Lowest standard rate available via online switch - 11.962p / kWh, Standing Charge 18p per day You have to be using quite a high % on the reduced rate to make any savings compared to a standard tariff. Link to comment Share on other sites More sharing options...
ProDave Posted November 22, 2016 Share Posted November 22, 2016 20 minutes ago, Stones said: Heating control 9.34p / kWh, Standard energy 18.5p / kWh, Standing charge 14.09p per day Lowest standard rate available via online switch - 11.962p / kWh, Standing Charge 18p per day You have to be using quite a high % on the reduced rate to make any savings compared to a standard tariff. Is that in Scotland though (if so tell me who) we seem to have an extra 2p per unit network charge up here compared to the rest of the UK that the price comparison sites don't mention and I have not yet found a way to avoid. Our standard rate at the moment is about 14p which when you allow for this 2p network charge, is not very much more at all. Another thing the SNP say they are going to address but have so far failed to do. Link to comment Share on other sites More sharing options...
Stones Posted November 22, 2016 Share Posted November 22, 2016 Seems to be Dave, that was the first result (on Uswitch) that came up available in our area - Economy Energy, https://www.economyenergy.co.uk/Compare/TariffSummary# although checking their website direct, they are showing 12.56p / kWh (after typing in our postcode) Link to comment Share on other sites More sharing options...
Nickfromwales Posted November 23, 2016 Share Posted November 23, 2016 If water pressure is shat, then I'd recommend a tank fed electric shower. This is basically a normal electric shower but it has a small ( integral ) impeller pump to 'suck' water from the header tank and that gets pumped into the shower to give you tidy pressure. Downside is a little noise of the pump running, but an excellent option as it's totally unaffected by other things being used in the house, ( which normally PLAGUE a regular electric shower to a point where they shut down completely and run stone cold ) so worth the trade off. Youll have to add a sister CWS tank if the one you have now is only 25 gal, as you'll need the additional stored water ( 2x 25 gal ) to feed the shower. All you need to do is plonk the tank alongside the existing one and add a low level connection. Doesn't need a ball valve or overflow etc, just one interconnecting pipe 22mm. Cut into the link pipe and tee out there to feed the shower. ? Link to comment Share on other sites More sharing options...
Crofter Posted November 23, 2016 Author Share Posted November 23, 2016 Hadn't heard of those, ta, but we have pretty impressive water pressure- we are directly downhill from the Scottish Water tank, with about 30m of head. When we first moved in I gave myself a fright when I turned the tap on! Link to comment Share on other sites More sharing options...
Crofter Posted November 23, 2016 Author Share Posted November 23, 2016 Oh by the way the only real alternative that I am considering is to fit an inline water heater rather than an electric shower. But I assume that this makes no odds to the electrics side of things? Link to comment Share on other sites More sharing options...
Onoff Posted November 23, 2016 Share Posted November 23, 2016 I have a pumped shower and it runs off a 25gal cws tank. Says so in the instructions that this is the minimum size. Seems to work alright. Link to comment Share on other sites More sharing options...
Nickfromwales Posted November 23, 2016 Share Posted November 23, 2016 6 hours ago, Crofter said: Oh by the way the only real alternative that I am considering is to fit an inline water heater rather than an electric shower. But I assume that this makes no odds to the electrics side of things? It would usually mean putting a 50a breaker and a 10mm cable minimum, bigger if the run is long. Some of the higher flow units are up at between 12 and 15kw, with the baby units around 9kw. Wattage divided by voltage gives you the current ( as a rough guide ), then allow diversity factor. 1 hour ago, Onoff said: I have a pumped shower and it runs off a 25gal cws tank. Says so in the instructions that this is the minimum size. Seems to work alright. Your supposed to add to the volume of CWS storage when you add a point of consumption The main problem is when your shower empties most, but not all, of the water from the tank and then the splashing water entering the tank stirs up the silt etc at the bottom of the tank. That then gets pulled into the filters of such devices and causes premature failure / excessively high maintenance intervals. The hot water cylinder requires a min of 25 gal and the shower the same, so running off one 25 gal tank will work if you don't shower excessively long or no one is using hot water at the same time, but is not recommended as it doesn't allow any redundancy / for the CWS not to be regularly depleted. Link to comment Share on other sites More sharing options...
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