Finding PROPER heating engineers in our area (Hants/Surrey)
- Thread starter Locoblade
- Start date
Who was it that said "if it wasn't for customers working for yourself is great"?
Hear all of these concerns nearly every single day but frankly they are not really valid IMO.
WB wireless stats (DT10 RF and DT20RF)can programme the preheat facillity for up to three times a day ensure maximum efficiency on the hot water side and these boilers (Greenstar CDis) also condense on the hot water mode however your demand for hot hoter is not excessive.
Losing power/water gas/electric is no big deal IMO .I mean we live in a civilised society how big a deal is it to be without heating or hot water for twelve hours every two years?
I've never been without any of those for more than 4 hrs in almost 30 years of married life and in any event all boilers rely on those three to work and if you have an electric shower,which you have then,you don't need an immersion heater and a 30 gallon hot water tank being constantly heating costing you an arm and a leg in the process 'just in case' do you?
Re,number four heating a small cupboard to dry clothes costs money and wastes energy and incourages damp so you will require some for of ventilation and all of this because you don't want a combi?
Drag yourself into the 21st century,you'll love it when you get there
Hi Tony
Cheers, I know some of the reasons may be trivial, and as mentioned some are the missus's reasoning rather than mine, but is heating a water cylinder really much more expensive?
The pre-heat on a combi uses gas, Im sure its not a huge amount but as there's no water capacity to store the heat I suspect its going to cool quite quickly and require fairly frequent firing to maintain? When you add in the bursts @ 30+KW every time you run the tap/shower, is it going to be that much less than heating a tank? Don't most HW cylinders recharge (from cold presumably) in less then 20 mins now? That wouldnt have the boiler running at the full 30Kw the same as the combi running because most system boiler dont seem to be that powerful, and won't they modulate even lower/be quicker if the tank is already warm?
This is me thinking purely off the top of my head so it may be completely wrong, but it seems to heat a tank of water each day will at most take ~20kw for 20 mins per day, although probably less. To run a combi with pre-heat will use 30kw every time a tap/shower is run and also a bit extra to keep the preheat going, so this if anything the combi seems to use more energy unless you have very quick showers and/or don't run the hot tap very often?
Not having hot water for a few hours wouldn't be a major concern no, but as mentioned if the boiler fails it could be several days before its fixed. Not a huge issue for adults, but getting a young family washed etc with a kettle/cooker as the only source of hot water would be a major PITA I would think.
When we re-do our bathroom I would consider going to a boiler heated shower, whether it was combi, or via vented or unvented tank, so the fact that we have an electric shower at the mo shouldn't be a deciding factor. Also, we don't actually use the airing cupboard for drying wet clothes as such, just keep bedding/clean towels etc in there so they are kept aired. TBH I wouldn't care if it wasnt there, this was another one of the missus's reasons why she didn't want a combi
Cheers for all the comments chaps, I'd be interested to know what you all know of the relative efficiencies of combis / stored water, but Im off for the weekend early tomorrow morning so no more replies from me until Monday.
When I do quotes for people who have a hot water cylinder with gravity primaries and no insulation on the cylinder I walk away from them clicking my heals.
Had a customer the other day who wants a new boiler. I suggested a 42 KW CDi combi but he wasn't keen so I set about persuading him then he told me his gas bills are £2K a year! Now this is a pensioner and his wife in a fairly decent sized house with one bathroom and kitchen and a pumped shower in the bathroom. The hot water is on 24 hours a day with the boiler on a low thermostat setting at number one in order that they can have constant hot water,unbelievable. The boiler is an old Netaheat 10-16 installed in 1983 or thereabouts.
I actually told him he could halve his gas bills by simply reprogramming his hot water demands.
To answer your question I think from memory the quoted figures for a hot water cylinder set up is about 25% of the cost of the total fuel bill, in the case above it will almost certainly be nearer 50% there is no way that a typical old style heating system can compete with a combi in terms of efficiency on the hot water side and even a top notch system with the newest boiler and controls ,unvented etc will struggle to compete with the hot water efficiency of a combi in terms of fuel used even against combis with a pre-heat and even with combis that can programme the pre-heat such as the ones I mentioned before.
Bottom line is you pay to heat anything so if you want stored hot water then that is going to cost you more than not storing it,obviously.
I tell customers that they can more or less halve their gas bills with a combi and they can and do make that sort of saving. One customer told me his gas bill had reduced by 60% and I personally pay £60 a month gas bill for a family of four (two teenagers) who, in a typical day have four showers and two baths, in a detached bungalow in Glasgow.
Tony.
Had a customer the other day who wants a new boiler. I suggested a 42 KW CDi combi but he wasn't keen so I set about persuading him then he told me his gas bills are £2K a year! Now this is a pensioner and his wife in a fairly decent sized house with one bathroom and kitchen and a pumped shower in the bathroom. The hot water is on 24 hours a day with the boiler on a low thermostat setting at number one in order that they can have constant hot water,unbelievable. The boiler is an old Netaheat 10-16 installed in 1983 or thereabouts.
I actually told him he could halve his gas bills by simply reprogramming his hot water demands.
To answer your question I think from memory the quoted figures for a hot water cylinder set up is about 25% of the cost of the total fuel bill, in the case above it will almost certainly be nearer 50% there is no way that a typical old style heating system can compete with a combi in terms of efficiency on the hot water side and even a top notch system with the newest boiler and controls ,unvented etc will struggle to compete with the hot water efficiency of a combi in terms of fuel used even against combis with a pre-heat and even with combis that can programme the pre-heat such as the ones I mentioned before.
Bottom line is you pay to heat anything so if you want stored hot water then that is going to cost you more than not storing it,obviously.
I tell customers that they can more or less halve their gas bills with a combi and they can and do make that sort of saving. One customer told me his gas bill had reduced by 60% and I personally pay £60 a month gas bill for a family of four (two teenagers) who, in a typical day have four showers and two baths, in a detached bungalow in Glasgow.
Tony.
D
Deleted member 105431
I totally agree. Combi's are far more economical than people think, and the reliabilty factor isn't an issue if you get a top branded one on a maintenance contract.
I can certainly see the sense in that. My own cylinder and primaries are ridiculously well insulated.
My old mum has a Profile 100E. I have been wearing myself out taking up the floors and putting BS Climaflex on the 28mm gravity F&R pipes from boiler to cylinder. (Used about 20metres of it), new jacket on the cylinder and an easier-to-understand Drayton SM2 programmer set for a few hours morning and evening.
Average daily gas usage this summer is now 22 cu ft, last summer it was 45 cu ft
I have also run 3&E for a cylinder stat while I had the floors up, but this can wait a bit.
Biggest problem I have when quoting for combis is trying to overcome the terrible reputation they have in relation to hot water and reliability which is really a myth for the most part but that reputation is ingrained in people's mind. Then you have the 'friends' who know it all and tell the customer that a combi isn't suitable for them on the basis that mate in the pub had one years ago and it took months to fill a bath
This thread is typical of the conversations I regularly have with people but I usually win in the end
I usually win in the end
JohnD would have said:"A cylinder is what I want and a cylinder is what I'm going to have. Do you want my money or not?"
Absolutely JohnD insulation and controls is the way to go if you want to store hot water.
I'm fed up telling people that the boiler has to be off in order that they save money.
Some people are actually convinced that TRVs are more efficient than room stats,they think I'm are talking nonsense when I tell them they aren't.
Then you have the low thermostat boiler setting brigade who think that if the water/house is always hot then it's cheaper to run the heating 24 hours a day rather than heating it from cold
I'm fed up telling people that the boiler has to be off in order that they save money.
Some people are actually convinced that TRVs are more efficient than room stats,they think I'm are talking nonsense when I tell them they aren't.
Then you have the low thermostat boiler setting brigade who think that if the water/house is always hot then it's cheaper to run the heating 24 hours a day rather than heating it from cold
I usually win in the end
JohnD would have said:"A cylinder is what I want and a cylinder is what I'm going to have. Do you want my money or not?"
Actually I walk away if someone want a cylinder and a boiler.
Only fitted one set up like that in the past five years and only because the house was massive and the hot water demand was large and the customer was a very very good payer
Did him a very nice set up too. WB 40CDi ,250 litre unvented copper cylinder from MacDonalds in Falkirk or somewhere north like that,wireless Honeywell stat and a bronze pump on the secondary return for the hot water. Hot water was amazing and instant at every tap,ended up fitting a steam cabinet for him too which is why I put in the unvented in the first place.
I asked him if he wanted the Honeywell wireless TRV set up too in order to save him money on fuel bills but he replied that he didn't have to bother about things like that,his motor is a Bentley GT something or other
Hi Tony
Cheers for the reply, it was the efficiency difference between those comparable brand new systems that I was wondering about, ie if the unvented cylinder would struggle to match a combi, by how much in terms of % gas used? If water is only about 25% of the overall gas in an average system, then there's less scope for significant gains/losses whatever water system is used. If for example a combi was able to supply water 3% more efficiently than a well lagged cylinder, thats only 3% of 25%, so less than 1% overall efficency difference / additional gas bill.
I can see the logic about if you want to store heat you'll need to pay for it because no cylinder is 100% insulated so you will lose some of that heat again, but is it really as simple as that? If both boilers are as efficient as each other, heating a given water quantity to a given temperature then yep, but is a combi running at full chat supplying a bath of hot water on-demand going to be running as efficiently for those 5-10m mins as if the water had been heated an hour beforehand into a highly insulated tank by a much smaller boiler running in its maximum efficieny window, which from my limited understanding is often not at max output like the combi would be running?
What I'm saying is, could it not be possible that heating water at optimum boiler efficiency over a longer period of time then storing it in a very well insulated vessel could in theory cancel out the losses in that system compared to a combi, if the efficiencies differ when they're actually heating the water? That is only an "if" though I concede, you guys may be able to answer if running a boiler at maximum output is as efficient or not?
You forget in the calculation, A combi is 10 x less reliable than a heat only boiler, and any gains plus a lot more besides will be eaten up in repair costs.
Efficient they may be, eco, friendly they certainly aint.
Get coat and exit quick
Efficient they may be, eco, friendly they certainly aint.
Get coat and exit quick
This is only my opinion but the combi vis the unvented is always going to be more efficient since you are not wasting energy storing water then constantly topping up that store however that is not the only part of the equation you have to take into account capital costs and in this respect the combi set is much cheaper and you have to think about your specific hot water requirements which all point to a combi.
A WB 42 CDi combi including flue warranty and serving for four years and DT10RF costs me about £1500 or thereabouts vs a WB 42 CDi conventional boiler ,flue warranty ,250 litre unvented cylinder and controls etc etc your talking well over £2500 possibly nearer £3000.
The relative efficiencies your talking about between the two set ups can probably measured in tens of pounds per year so obviously a combi set up is much more efficient and even more so if you go for a cheaper boiler such as a Main or a VoKera which will take about £750 off that total of £1500.
Bottom line is you pay your money and all that.
A WB 42 CDi combi including flue warranty and serving for four years and DT10RF costs me about £1500 or thereabouts vs a WB 42 CDi conventional boiler ,flue warranty ,250 litre unvented cylinder and controls etc etc your talking well over £2500 possibly nearer £3000.
The relative efficiencies your talking about between the two set ups can probably measured in tens of pounds per year so obviously a combi set up is much more efficient and even more so if you go for a cheaper boiler such as a Main or a VoKera which will take about £750 off that total of £1500.
Bottom line is you pay your money and all that.
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