Combi boiler or electric shower?

[Littlepeahead]

Morning Org. Any boiler experts on here?

At home, a 1980s house, I've got storage heaters so for hot water there's a tank in the airing cupboard with an immersion on one of those timers you normally use for a table lamp for security. This means the water heats up twice a day like a big kettle then there's a pump for the power shower.

It's fine when on a regular day as I shower morning and Mr LPH evening but if we have friends over there's not enough water for more than 1 decent shower from the tank.

I don't use much other hot water as I have a dishwasher.

I don't want a dribbly rubbish shower as my power shower is the only thing that makes me capable of functioning each morning.

So what would be my options to replace this rather rubbish system? And the sort of cost?

[daveyrach]

I work for a boiler company but am no expert but I would sat combi all the way, you would get hot water at whatever you mains pressure is meaning no need for a power hungry electric shower.

[Phoenix22]

I work for a boiler company but am no expert but I would sat combi all the way, you would get hot water at whatever you mains pressure is meaning no need for a power hungry electric shower.

That's not exactly true, hot water via a combi will never be at full water main flow rate as the boiler needs to slow it down to be able to heat it. Hot water flow rates are quoted in the boiler specs so you need to look at this if you go combi, as some of the cheaper ones flow really slowly.

Obvious question really but do you have gas in the property?

[Dave-the-rave]

I have the same sort of rubbish system in a rented property. I installed an electric shower 10 years ago and haven't had the hot water on since. Seriously. I boil the kettle once a day for dishes.

[Specialone]

Combi all day long, next question.

[daveyrach]

That's not exactly true, hot water via a combi will never be at full water main flow rate as the boiler needs to slow it down to be able to heat it. Hot water flow rates are quoted in the boiler specs so you need to look at this if you go combi, as some of the cheaper ones flow really slowly.

Obvious question really but do you have gas in the property?

I'm well aware of that, but they are a damn site better than these carp power showers that slow to a trickle when you get a tiny bit of scale in them. I'd have a combi boiler all day every day, I mean why wouldn't you?

[johnnyrod]

Unvented hot water cylinder, just get a larger one than you have now. near-mains water pressure (regulated to 3 bar typically, which is plenty) at all the hot taps, so an ordinary mixer shower will Karcher your ass. They're not cheap though.

[Littlepeahead]

No gas.

I'm guessing our shower is simply pumped straight out of the vented tank, the pump is also in the airing cupboard and we've got the biggest tank in there you can fit. It's a1050 x 450.

[Bibio]

dump the system fed power shower and fit a good on demand power shower.

this frees up the boiler for other duty's such as dishes and stuff.

[PyroUK]

I changed a couple of years ago from conventional to combi, don't know how I managed to live before hand. Didn't even have a power shower. :-o

Only thing about that is that you need to have sufficient mains pressure otherwise you are stuck with conventional (or at least that's what boiler man told me).

Plus you have the benefit of hot water when you need it and not wasting if no hot water is needed (holidays/you decided you want to be scummy and lazy/etc)

[cb1000rsteve]

IMO electric shower. If you have solar panels you can fit a low powered immerse ion heated that is on continuously during daylight hours. I have this and never runabout of hot water. If no panels I'd use an electric shower as it's the cheapest option and now days they are very good

[Specialone]

Decent 10kw electric shower and cable to supply it with fitting around £500, probably last 5-10 years at most, cheap mixer to run on a combi £50, (excluding boiler cost) last 5-10 years, replace for another £50 one.

£50 cheap mixer out performs electric shower easily unless a power shower (pumped), no contest IMO.

[Phoenix22]

No gas rules out the combi option then.

[daveyrach]

LPG?

[PyroUK]

No LPH!

[Amadeus]

Can you post some pics of you in the shower so that we can see the sort of pressure you're currently getting?

Unvented are like the Megaflow systems? I heard that you can experience problems when you install them as weaker joints could burst but they're jolly good when up and running.

[Littlepeahead]

I think there's a gas pipe into the house but the previous owner got rid of the gas supply. But then he also installed this system of heating and hot water. Bodger Pete did a lot of odd stuff.

[zxmark9r]

Morning Org. Any boiler experts on here?

At home, a 1980s house, I've got storage heaters so for hot water there's a tank in the airing cupboard with an immersion on one of those timers you normally use for a table lamp for security. This means the water heats up twice a day like a big kettle then there's a pump for the power shower.

It's fine when on a regular day as I shower morning and Mr LPH evening but if we have friends over there's not enough water for more than 1 decent shower from the tank.

I don't use much other hot water as I have a dishwasher.

I don't want a dribbly rubbish shower as my power shower is the only thing that makes me capable of functioning each morning.

So what would be my options to replace this rather rubbish system? And the sort of cost?


Your tank holds about 120 litres of hot water, if you assume a 50/50 or less mix with cold water (depends on tank temp & how hot you have your shower) and your shower delivers 12litres a minute you will run out of hot water in about 20 minutes or less.
You could turn the immersion heater thermostat up which would help, or increase the time that the immersion is on. if you want hot water (for your guests) after you have showered you probably need to have the immersion on for another 30 minutes to allow it to recover.
I have the same size tank as you and we have a family of four (3 of us shower daily, the 10 year old boy only when I make him:) ) and we never run out of hot water.
If the heater doesn't recover fully in 40 minutes you may need a new immersion element, these are only about £15 in Wickes.
Hope this helps.
Mark

[Littlepeahead]

After an hour hearing in summer, with the shower on half power which is fine on our shower at warm temp you'll get a 5 to 6 minute shower. The element is fine but if you set it over 60 degrees it trips and needs resetting. If the timer comes on in the morning and that water isn't used and then it comes on again it also trips. The element isn't very long, only goes about a third of the way into the tank, is that normal? It can't be changed without removing the whole tank.

[Dave-the-rave]

Does the tank have bricks in it like a storage heater?

[Red ones]

Is the tank scaled up?

[Littlepeahead]

Tank was brand new 6 years ago, element is around 4 years old.

[Sid Squid]

That's the wrong element, it should reach to within a few inches of the bottom of the tank. A short element will heat the water in the top of the tank which sticks there as it's less dense, and causes the thermostat to switch off before the whole tank is heated sufficiently.

[Luckypants]

Combi all day long, next question.Why?

There are other mains pressure hot water systems out there that deliver better flow and more consistent pressures. So why a 'combi everytime'? As you are a professional Phil this is a genuine question of interest for your opinion. (sorry in advance if this hijacks your thread LPH)

[johnnyrod]

If the immersion is fitted in the side of the tank then its length is almost irrelevant. if it goes in through to top then of course it needs to be long. Unvented water cylinder comes with an immersion heater. It's an expensive way to heat though, just electric, depends if you want to look at the cost of getting gas back in.

Re. water temperature, 60C is the benchmark, hot enough to kill legionella, but any more and it starts to scale up - you will have a safety thermostat that is tripping if you try to turn it much above 60C I am guessing.

[Specialone]

Why?

There are other mains pressure hot water systems out there that deliver better flow and more consistent pressures. So why a 'combi everytime'? As you are a professional Phil this is a genuine question of interest for your opinion. (sorry in advance if this hijacks your thread LPH)


It's the best all round way of doing it IMO Mike, the other systems are more expensive, require more space as they still need a tank.

I think the question was electric or combi, not what other options does she have, I answered the question and still stand by my answer.

[Spiderman]

All i know is that you need to see me when it comes to your shower head :) And that the Squid is rigth about the element length too, sometimes size really does matter!

[zxmark9r]

After an hour hearing in summer, with the shower on half power which is fine on our shower at warm temp you'll get a 5 to 6 minute shower. The element is fine but if you set it over 60 degrees it trips and needs resetting. If the timer comes on in the morning and that water isn't used and then it comes on again it also trips. The element isn't very long, only goes about a third of the way into the tank, is that normal? It can't be changed without removing the whole tank.


I don't think the electric should trip out, a thermostat is there to stop the water overheating, and it should go on and off at will as required, not trip out.
The Thermostat/safety control switch could be faulty, the link below shows you how to change it:
http://www.youtube.com/watch?v=td3SuGeTefM


Mark

[Littlepeahead]

I think what happened is that the he fitted the tank after we viewed the place as the existing tank burst. I think he put too short an element in. Trouble is the clearance above the tank to the ceiling is not much so you can't physically fit a longer element without removing the whole tank. I've always suspected that is why we've got a huge tank but not a lot of hot water.

[PyroUK]

What's the ceiling material? Can you remove part of it temporarily?

[maviczap]

In our previous house, we had the standard gigantic tank replaced with a mini tank. The benefits were that the tank heated up within 30 mins. Plenty enough water for showers & it filled a bath with enough hot water.

It was quick enough to re heat the water for another shower very quickly, so no problem if you had guests.

We had a gravity fed shower which was bloomin good on this system. If I remember correctly that was electric.

We have a combi boiler and shower in our present house, no need for a pump, as mains pressure is good enough. But the combi can't cope with another tap being turned on, without the shower going cold.

I preferred the mini immersion tank system.

I wouldn't go for an electric shower

[NTECUK]

Best rip it out and do it properly.
It likey save money by being more efficient.

[dirtydog]

Ok lots of answers here. But it will depend on what you're actually trying to achieve?
Is it just the lack of hot water that's the issue?

Has it always been like this or is it something recent?

Your cylinder will hold about 140 litres of water which should be more than enough for a couple of showers although that will depend on what shower pump you have.

Combi boilers are good if you have decent incoming water pressure as are unvented cylinders as are electric showers but they all come at a price.
For example- normal vented cylinder 1050x450 would cost about £180 from my local merchants whereas an unvented (megaflo) the same size would set you back about £750.
Decent electric shower (9/10kw) will set you back £300+, then of course you've got the cost of the cable, and possibly an rcd shower add on if your consumer board doesn't have a spare way in it.

So it really all comes down to what you want to achieve and how much you want to spend?

I've come across loads of 1050 cylinders fitted with 11" immersions so I wouldn't be surprised if it does have the wrong size in it

[thefallenangel]

At £1500-£2000 for a combi boiler, I would go with that but it does leave you without heating + hot water when it does pack up. If you can repair yourself (everything bar breaking gas connections) then fine if spares are available. I got a 30kw Worcester Combi Boiler and its been good. Runs 7 radiators with BTU of about 15,000 and a shower easily.

[munkygunn182]

Pretty much what TFA said. I service boilers and showers day in/day out. If you're going combi, make sure it's got the capacity to run your heating + shower + potentially a hot tap or the likes. Have a back-up plan for when it packs in - note that's when, not if.

If you're going down the route of an electric shower you could well get just an instant one without the pump etc (if they're still on - I'm stripping out a hotel that's got millions of them at the moment). At the end of the day, it's convenience - what works best for you?

[Littlepeahead]

Ah right so combi does heating too? Well I don't need that. Got one storage heater in the living room and we use that in winter, and another on the landing that only goes on if the outside temperature drops below freezing, otherwise we don't use it. House is really well insulated.

Everything goes in the cold fill dishwasher and washing machine so I use virtually no hot water other than for showers. Just a bowl full when cleaning the kitchen surfaces.

Sounds like I need to get the element changed in the tank more than anything.

[DarrenSV650S]

Ah right so combi does heating too?

On page 4?? What has been happening in this thread? :confused:

[Red ones]

Thought I'd wait before I wade in.

So, you have a power shower and like it. You don't use much hot water and don't need heating?
I'd either replace the immersion element with one that is longer, or see if a small pump can be fitted to the tank to destratify the water. A destrat pump just mixes the hot water at the top of the tank with the cold at the bottom. It would mean you get kore hot water for your shower and reduces the chance of bugs growing in the tank.
The other solution is to go to an electric shower and ditch the idea of the immersion tank. But that means the shower becomes relatively gutless and if you like the power shower then you would be disappointed.

[Specialone]

Ah right so combi does heating too? Well I don't need that. Got one storage heater in the living room and we use that in winter, and another on the landing that only goes on if the outside temperature drops below freezing, otherwise we don't use it. House is really well insulated.

Everything goes in the cold fill dishwasher and washing machine so I use virtually no hot water other than for showers. Just a bowl full when cleaning the kitchen surfaces.

Sounds like I need to get the element changed in the tank more than anything.

Insert double face palm pic of your choice here :rolleyes:

[Littlepeahead]

As you can tell I am fairly ignorant when it comes to heating and hot water systems.

I guess the simplest and most cost effective solution is that when friends come to stay we all shower together, problem solved!

[johnnyrod]

I was thinking this over again and with your extra info about size of tank, length of heater etc then yes, just getting the element changed for a longer one will be the easiest and cheapest option. If you can't fit it in situ you may have to drain the tankentirely so it can be decoupled and moved so you can get access (worst case) but if the amount of hot water is your only beef, then yeah do this. Not worth getting a boiler

Re. combis breaking down - why do you say when not if?

[NTECUK]

To there's not much point in heating a tank of water just for a shower.
If you are lucky enough to have good mains pressure go instant electric
Or you can get a powered instant lecy shower too

[johnnyrod]

On the sinks as well? The cost of getting a new immersion element is going to be pretty small compared to changing the entire installation

[thefallenangel]

Question, looking to extend my house adding an ensuite and extra bedroom but don't want to pull all the floors up and mess around with pipework. Can I add a 24kw combi boiler (extension)with a 30kw one(main house) or will i have to go electric heating and shower

[munkygunn182]

Thought I'd wait before I wade in.

So, you have a power shower and like it. You don't use much hot water and don't need heating?
I'd either replace the immersion element with one that is longer, or see if a small pump can be fitted to the tank to destratify the water. A destrat pump just mixes the hot water at the top of the tank with the cold at the bottom. It would mean you get kore hot water for your shower and reduces the chance of bugs growing in the tank.
The other solution is to go to an electric shower and ditch the idea of the immersion tank. But that means the shower becomes relatively gutless and if you like the power shower then you would be disappointed.

The destrat pump isn't a bad shout, though is generally more effective on bigger cylinders as the area below the first heating element may well be measured in meters rather than millimetres.

If you don't need heating covered and it's purely for bathroom purposes then I'd look at either an instant heater or a combi boiler, unless your cylinder is on a timer. If the cylinder is to stay, look at more powerful immersion coils to heat the water faster, but beware that bigger coils may require chunkier wiring.

[munkygunn182]

Question, looking to extend my house adding an ensuite and extra bedroom but don't want to pull all the floors up and mess around with pipework. Can I add a 24kw combi boiler (extension)with a 30kw one(main house) or will i have to go electric heating and shower

Nothing to say you can't (I believe), but does the cost of two boiler units + related gas works/electric works still come out cheaper than pulling up floors?

[thefallenangel]

Nothing to say you can't (I believe), but does the cost of two boiler units + related gas works/electric works still come out cheaper than pulling up floors?


It works out about £1000 for one installed which will run the extra radiators and electric shower. None of my rads are currently where i'd need them for the extension either

[Viney]

Morning Org. Any boiler experts on here?

At home, a 1980s house, I've got storage heaters so for hot water there's a tank in the airing cupboard with an immersion on one of those timers you normally use for a table lamp for security. This means the water heats up twice a day like a big kettle then there's a pump for the power shower.

It's fine when on a regular day as I shower morning and Mr LPH evening but if we have friends over there's not enough water for more than 1 decent shower from the tank.

I don't use much other hot water as I have a dishwasher.

I don't want a dribbly rubbish shower as my power shower is the only thing that makes me capable of functioning each morning.

So what would be my options to replace this rather rubbish system? And the sort of cost?
We have both. A Combi Bolier and Electric shower. The water pressure is shocking during the summer months.

[NTECUK]

We have both. A Combi Bolier and Electric shower. The water pressure is shocking during the summer months.
My sisters old house had a lecy one with a feed from the hot and cold that had its own pump inside,a sort of hybrid power shower

[dirtydog]

We have both. A Combi Bolier and Electric shower. The water pressure is shocking during the summer months.

If you do have low water pressure you can get pumped electric showers

[NTECUK]

If you do have low water pressure you can get pumped electric showers
But you will need a cold feed from the storage tank

[Viney]

My sisters old house had a lecy one with a feed from the hot and cold that had its own pump inside,a sort of hybrid power shower

If you do have low water pressure you can get pumped electric showers

We used to have a shower running off the combi many years ago. This was before the days of pumps. Since then my day a long time ago fitted an electric shower. Havent got the time, effort or knowhow to swap it back. It works thats the main thing.

[NTECUK]

. It works thats the main thing.
yep good enough.
I was looking at Triton T150Z Pumped Thermostatic Electric Shower for mumzy.
Dont know if they are that quality??