I'm hoping I don't need a new shower unit here so any ideas or how to fix the following problem would be appreciated.

I bought the house last June and everytime I turned the electric shower on the lights in the house would dim slightly until I turned the shower back on again. Normal I think due to the high current its using?

But last week my girlfriend said she noticed that the light on the shower cord unit (bit attached to the ceiling) would blink and the water would go cold for a second before the light came back on. I could live with that, but its got progressively worse. Now its...

Pull cord to supply power to the shower
I turn on shower
Light turns off immediatley (shower has no power, so cold water)
I turn off shower
Pull cord (off)
Pull cord (on)
I turn on shower
Light turns off after 0-30 seconds
Repeat

Its doing my head in :-( Any ideas?

Edit: When I pull the cord the 'power light' can stay on for hours. Its only when I draw current that it goes off.

What a coincidence, my first experience using an electric shower was yesterday, here in Peterborogh where we're staying. I didn't even know such a thing existed.

It certainly sounds like a problem with current draw, doesn't it? Or perhaps a problem with the wiring. If the correct fuse is on the circuit with the power supply to the shower, then there might not be an actual wiring short (the fuse should blow if that's the case). Maybe there's something wrong in the electric unit itself, such as a failing heating element, that's causing too much current draw?

Or maybe it's simple and it's just the switch attached to the pull cord that's shorting out.

Sounds to me like a bodge job by an electrician which, as often happens, takes a while to manifest itself: Sounds as so the shower and light are on the same circuit/spur. I don't know about the US, but here in the UK, we have separate lighting and power circuits, but both things often end up on a lighting circuit.

It took me years with my shower, clearing up damp, to figure out that the extractor fan had been put in upside down and was blowing steam around the bedroom!

Not normal. Get an electrician in, but defray some of the cost by installing a swearbox for when they venture their opinion of whoever did the previous installation.

Peter

"Who the 'ell did this then"

The trouble is that the next electrician is probably as bad as the last one!

I was sitting quietly in boxer towers the other day when the electricity tripped off: Mrs. Boxer said that there had been blue flashes in the utility room.
On investigation, a 5ft. fluorescent fitting had fallen off the ceiling: The electrician had put it up on a panel ceiling with two masonry plugs of different sizes, one at one end and one in the middle, so the whole time that it had been up, it was levering itself off.
A swearbox would have been too good!

My apologies, but could someone explain to me what an electric shower is? Personally, I'd rather not be showered with electricity

It's a shower that has only cold water plumbed to it, and incorporates an electric water heater. Considerable care is taken to avoid failure modes that involve being showered with electricity.

A shower that has both hot and cold water plumbed to it, but incorporates an electric water pump, is known (following a successful advertising campaign) as a power shower.

Peter

It does sounds like you need a good electrician to take a look at that. An electric shower should be on a separate breaker on your dis-board take a look and see if anything is labeled up, if it isn't then maybe a bodge job tapped into the ring main or something. They should be fed like an electric oven feed not with standard 3.5 twin and earth.

It could also be a water pressure problem, unlikely but possible. An electric shower will cut out if the pressure drops too low, this is to prevent the water getting heated up too much and burning you when you are stood under it. If there is a problem with this system then maybe that is causing it?

Cheers

Cris.

Get an electrician (or plumber?) in to check it out.

In the meanwhile, you can try (workaround) turning down the temperature dial (if it has one) in increments of 20% or so, and see if that helps. It did at several of the B&Bs we've stayed at over there.

Theory being, that the water was too cold for the size of heater/circuit to keep up with, and the heater actually, well, overheats, and then shuts itself off for safety reasons.

A slightly lower output temperature can allow things to muddle by until the root cause is fixed.

Cheers

Unless you're a US military contractor.

I think it's one of these

No, not one of those, one of these

Do I take it that electric showers are a UK thing then?

I wish we didn't have them, never been in one that has been any good. My showers are fed from the hot water tank, and can't really understand why people would have an electric shower out of choice.

I know there are lots of safety measures in place, but there is something a little but wrong with standing under a stream of water that passes just a few mm away from a pretty hefty mains supply, you'd only get a belt for a very short period of time but I am sure it would still give a nasty nip to your shower!

Cheers

Cris.

I think the reason is that most hot water tanks aren't large enough for a couple of pumped showers along with other hot water use. Possibly they are reheated more quickly by dedicated hot water heaters used in other countries.

The place I just bought has a shower hose from the mixer tap attached to a wall bracket, although since it's a gravity-fed hot water system there is under a metre of head so it's a pretty weak flow. I will probably fit a pump sometime, since a normal cylinder will have enough hot water just for me.

Yeah. In the US basically every shower is hooked up to the same hot water source as everything else in the house, which, traditionally, is a thirty to fifty gallon insulated tank constantly kept at temperature by an electric or gas heating device, called a "hot water heater", though there have been significant inroads made by tankless water heaters in the last ten years or so.

I'm sure that one of the reasons that we don't have electric showers is because the vast majority of power in a US home is 110V, which probably isn't even close to enough to heat water that quickly. (Generally, the only 220V connection is for a clothes dryer.)

220v also for non-gas range. Which is standard in pretty much all homes.

And an electric shower should, unlike Phil's, be hard-wired in on its own circuit, just like an electric cooker. Even in good old 240V Blighty, you can't just plug such things into normal 13A sockets.

Peter

Right. I always forget about that one.

So you have a 110v AND a 220v supply in your homes ??? I don't get that. Why not just have 220v everything ???

I think I'm right in saying that hot water tank systems like mine can no longer be fitted in the UK, the legislation says a combi boiler must be fitted which heats the water on demand. My house was built just before the legislation came into effect, and the houses that were completed towards the end of the site build have totally different heating systems in them.

Cheers

Cris.

I have no answer to this. I'll just chime in and say I have one 220v circuit in the house for an in-wall air conditioner.

My house is heated by natural gas, so other 220v circuits aren't needed.

I'm not an electrician, but, as I understand it, homes get 240V from the power company, but it gets split to 120V for regular outlets. Basically, all electrical circuits have three conductors. One is always ground. For the other two, on 120V circuits, one is "hot" and carries 120V and the other is "neutral" and carries no voltage. On a 220V circuit, one is the same 120V as the "hot" on the regular outlets, and the other is also 120V running out of phase, so that the voltage difference between the two is 240V.

In reality, it's actually just a single 240V single-phase circuit, and the "neutral" is a center tap.

In more commercial settings, the power company provides three-phase power and there's about 240V between any two of the three phases. (I think it's actually 207V.)

There seems to be a lot of confusion over 110/220 vs 120/240. I'm not sure which is correct, to be honest.

I'm not an electrician, either, but I assume that they both refer to the same supply ('generic house voltage').

Actually, at any given moment your supplied voltage might be as low as 105 or as high as 120*.


*not based on any scientific study- just what I've noticed.

Yeah, that's certainly true, but I'm sure there's a nominal voltage that they're aiming for.

Maybe this thread can answer something that I've puzzled over for a long time, in the UK we have 230v, but on construction sites we have step down transformers and generators that supply 110v for all the relevant machinery...why!

In the meantime I've checked out both the electric and gravity fed showers in my house and they seem to offer about the same pressure shower.

According to the internets, it's a safety issue. Apparently it's actually single-phase 110V, 55V on each leg, and I guess the thought is that it's unlikely that 55V will kill you whereas 230V definitely can.

Very commonly used in places like Singapore and Malaysia but there generally you don't want too much heat in your hot water. Confuses people the first time that they have to turn the switch on outside the bathroom first.

Where it becomes a nuisance I find is that because there is no central hot water, there is not hot water in the kitchen (without boiling a kettle) to wash up. Commonly also the bathroom basin isn't connected either (i.e. it's just the shower) so if you want a decent shave with hot/warm water you're out of luck...

Are not the electric showers equipped with GFIC.

My house in Singapore had the worst possible hybrid of these systems, American style stupid tank water heater, but only 8 gallon, electrically powered, no gfci, and mounted directly over the shower head. It was good for about 5 minutes of hot shower...

I used an electric shower in Brazil one time. That's all I have to offer.

Significant inroads yes, but the installers - at least in california - have not caught up yet. When I got my place over here it had a 30+ year old boiler which was dead, plus a huge hot water tank thing.... so I got a super-efficient combination boiler installed for the underfloor heating (original 1950's pipework!) plus hot water, meaning I could lose the tank heater. I picked a Laars 330 which appears to be a Baxi 330 in the UK.

It's great, apart from:

a) the installer didn't have a combustion analyzer and hence couldn't set it up in the first place until he bought one. Seems that you don't need anything like that to install "normal" boilers

b) it's now in a state where we pretty much don't get hot water unless we turn the heating on first. For some unknown reason the controller on the boiler just cycles the flame on and off if we turn the shower on, giving you lukewarm but never hot water.

If the boiler is lit already, heating the underfloor pipes, and switches to hot water (water always takes priority) then we have all the hot water we ever need.

More than a year later and he's still coming back and looking confused, and claiming the distributors of the boiler just don't give him any tech support. I've now installed a webcam pointing at the status lights on the boiler so I know, when I turn the tap on, whether the boiler is going to cycle or actually stay lit... yes, it's that ridiculous

I would break out the soldering iron, scope, meter and so on but gas frightens me...

Grin. You don't trust yourself around gas, and I completely understand that point, but you trust your installer who we KNOW doesn't know what he's doing?

To be honest, I find the whole thing about number of bends in gas pipes between feed and boiler/BTU calculations seems to be very... vague. This stuff was needed for the city permit (again, something which I, uhhh, didn't do in advance because in the UK you don't ask the council when you want to change your boiler).

I never thought gas would have problems getting around corners, but it seems that it does, allegedly. Anyone know WHY?

Corners? Are you talking about gas supply or venting pipe? I'm not a pipefitter, but I've talked to a number of them while they worked on various installation I've had done. Never heard any of them mention anything about restriction on bends/corners of the supply side, only with the venting. Usually the supply restrictions were about pipe diameter and position of valves.

A corner restricts the flow, so there are charts of "equivalent added feet of straight pipe" for corners, with different values depending upon the angle/radius of the bend.

The pipe diameter also affects resistance-over-length.

So for a required flow rate (so that the instant-heater doesn't choke), there's a limit on overall length, taking into account all of the bends. Exceeding the limit, means moving up to a larger ($$) pipe diameter.

Or so the gas man said.

It's the same sort of flow calculations I had to do when sizing the dust collection tubing for the workshop.

Cheers

If it's a Baxi, try this site - the people on there know quite a bit, if you explain the problem with deftails of the status lights for each stage of the problem they should be able to suggest things to try.

The flame cycling sounds like the sensor isn't detecting that the main burner is lit, and turning off the valve and then starting over.