Can a shower be added to my consumer unit?

[EddieM]

Hmm, ok but 100% is 100% not 99 etc. Then some manufacturers of gas boiler claim > 100% efficiency, which is a physical impossibility.

 

[Harry Bloomfield]

Then some manufacturers of gas boiler claim > 100% efficiency, which is a physical impossibility.

I very much doubt it, can you provide a link to such a claim?

 

[EddieM]

I very much doubt it, can you provide a link to such a claim?

Its been "discussed" many times on this fora, not this particular forum., I can't be bothered to find the post, as its all nonsense anyway. Feel free to search of course.

 

[SUNRAY]

Looking as subsequent replies it appears 1 is not wrong.

So that leaves 2. So it appears that bully SUNRAY does not agree that electrical heating is very expensive. Interesting. He must be very wealthy!

Do you know anything Winston?

If you do, please let me know what typical flat rate unit costs of gas and electricity

 

[Harry Bloomfield]

Its been "discussed" many times on this fora, not this particular forum., I can't be bothered to find the post, as its all nonsense anyway. Feel free to search of course.

I really would not waste my time, you made the statement - you back it up with a URL.

I have though seen ads where they suggest electric heaters can be much more efficient than 100%, using weasel words.

 

[EddieM]

I really would not waste my time, you made the statement - you back it up with a URL.

I have though seen ads where they suggest electric heaters can be much more efficient than 100%, using weasel words.

Ok, here's a URL that explains how figures of >100% have been "quoted" as said though and explained in the article, it's misleading (rubbish)

https://ianbgas.co.uk/technotes/Gross-and-net-and-weird-efficiency.html

 

[JohnW2]

I turn the shower on, then just seconds later it is running hot water. A combi takes a while for the water to warm up in the boiler, then make its way through the pipework.

Well, quantitatively obviously 'depends'. In my daughter's Georgian cottage (which has ceilings so low that I sometimes hit my head on them) there is a combi in the kitchen and a bathroom immediately above, with the shower more-or-less directly above the combi. The pipe from combi to shower mixer cannot be more than about 5 feet in length (and that to the bath and basin taps even shorter), so that 'full temp hot water', appears at the mixer and taps essentially 'immediately' (within, say, 5 seconds at most). That wait certainly would not significantly prolong the amount of time it took me to have a shower

When you finish your shower their is a lot of wasted hot water in the boiler and in the pipework.

I have acknowledged those 'losses' (as far as water heating is concerned) but they are no great and, as I've said, for a substantial proportion of the year they merely provide useful space heating (i.e. not lost/wasted energy or money).

Kind Regards, John

 

[SUNRAY]

One of my flats has a combi and the pipe to any hot tap is about 4.2m or thereabouts which I would have thought would not be atypical and with a totally cold boiler I'd say it takes about 20-30 seconds to be fully hot, if the boiler is fully hot in heating mode I'd say 5 seconds tops.

My daughters house being a 4 bed property takes much longer than those.

 

[JohnW2]

One of my flats has a combi and the pipe to any hot tap is about 4.2m or thereabouts which I would have thought would not be atypical and with a totally cold boiler I'd say it takes about 20-30 seconds to be fully hot, if the boiler is fully hot in heating

Yes. The water coming out of the boiler's head exchanger will presumably be 'fully hot' more-or-less 'immediately, but it obviously has to displace whatever cold/cool water is in the pipe before that hot water comes out of the other end - so the time delay will be critically dependent on the length of that pipe.

Kind Regards, John

 

[winston1]

Do you know anything Winston?

If you do, please let me know what typical flat rate unit costs of gas and electricity

Why don't you look at your bills? They will have the information you are asking me for. It has been stated many times on these forums that electricity is around 4 times the cost of gas.

 

[SUNRAY]

Why don't you look at your bills? They will have the information you are asking me for. It has been stated many times on these forums that electricity is around 4 times the cost of gas.

Because you're the one that keeps telling me that and I want to reply to your incorrect statements, I'd like you to look at your bills and supply that information.

Please.

 

[Harry Bloomfield]

Why don't you look at your bills? They will have the information you are asking me for. It has been stated many times on these forums that electricity is around 4 times the cost of gas.

I don't think anyone would argue about the difference in cost, but basic fuel cost is not the only factor in making a decision.

 

[winston1]

I don't think anyone would argue about the difference in cost,

Well SUNRAY does.

As he won't believe it but my electricity from eon is 16.822p per kWh and gas is 2.941p per kWh. So yes I was wrong to say electricity was 4 times the cost of gas, it is actually 5.7 times the cost of gas.

 

[RF Lighting]

Hi @winston1 please can you reply to this post.

@winston1
The works discussed here appear not to be restricted under the legislation in ROI. As @BS3036 has kindly illustrated.

It may be that you have some additional information that others are missing (I can't see it). I would like to be educated on this (you like to do that).

Now you have read the legislation, and to give you an opportunity to clarify, please can you indicate which part of the legislation restricts the OP from fitting a Hive to his Firebird. Or apologise and retract your post.

 

[SUNRAY]

Well SUNRAY does.

As he won't believe it but my electricity from eon is 16.822p per kWh and gas is 2.941p per kWh. So yes I was wrong to say electricity was 4 times the cost of gas, it is actually 5.7 times the cost of gas.

My God what on earth are you paying that price for, I assume it's something like a key meter.

I'll base my calculations on my shower habits:
2 minutes/60 x 16.822p x 7KW [my Triton shower on low power] = 235.508/60p = 3.923p
2.5 minutes/60 [to allow for the time taken for the combi to strike from cold and the water to get to the shower, see quote below] x 2.941p x 27KW = 198.5175/60 = 3.31p

So on your expensive tarriff I'm very happy to agree it makes your electric shower more expensive than gas.

However my energy prices are 12.4p and 2.78p with BG equate to:
Electric 173/60p = 2.89p
Gas 187.65/60p= 3.128p

Which makes my electric shower cheaper than gas.

Neither of these have taken account of the electric power used by the gas combi.

In addition to the energy costs are the water and as we are on a meter that means 25% extra.

From a PM to another member earlier:

I've just heard from a colleague, I asked him to do some tests on his combi using his calibrated IR thermometer. He got home from work with no heating on all day.
DHW pipe exiting from boiler 8° time to reach 40°=17seconds and time for bath tap to reach 40°=43seconds and 60°=68 seconds. that included the time taken to heat the metal tap so I don't think allowing 30 seconds for the water to be a sensible usable temperature is too far out.
His house is a fairly typical developement 3 bed semi of about 5-7 years old and serviced every year by installers.

Elsewhere the discussion about modulation has cropped up, it is my belief that little, if any, modulation will occur during a 2.5 minute shower. I don't have a combi to be able to take any readings.