Need to replace Central heating boiler? Getting conflicting advise? Combination or Conventional or Mega flow?
Question:Hot water runs out and I am told that it is because of scale in the hot water tank. The boiler is old as well so thought about changing . Conflicting advise recd- one ENGG said that Combi will be perfect, the other said the opposite. A friend suggested Mega flow system. Any suggestion will be appreciated and indication of costs will be welcome.
Answers:
Both of these systems have their own merits & both will reduce your gas consumption. Choice of which to have installed will be dependent on a number of considerations.
1,water mains size
2,water pressure, bars
3,water flow, litres per min
4,water requirememts, number of hot & cold outlets
5,household occupancy
One bedroom flat 2 adults = Combi
Two bedroom 1 bathroom house 4 adults = Combi or Megaflo
Four bedroom 2 bathroom house 4 adults 2 kids = Megaflo
As for cost, It is difficult, Expect to pay between £1500 & £6000 Depending on work involved & materials required
Your corgi registered installer will be able to work out your requirements.
Ask friends, neighbours, work collegues for recommendations.
CORGI will also give you the tel no's of local installers.
0870 401 2300 www.trustcorgi.com
We use megaflos.
We have 2 of them but our house is 5 bed/5 bath and in 2 "wings" so it made sense to have 2. a normal 3 bed house would just need one, 180 or 210 Litre.
In our last house we had a combi boiler that was the right spec and a decent make, but i found i never had a hot shave in all the time it was installed. i just couldn't be bothered waiting for the hot water to heat up the exchanger and then come through the pipes.
Our megaflos are 300L each and can cope woth 5 baths and 5 showers all at once. Full 4 bar pressure on hot and cold. And as we've got electric elements in them as well we don't need to turn the oil boiler on during the summer.
A megaflo stays hot for days and days. really good insulation and guranteed for 25 years.
fantastic.
Doesn't sound like scale to me. If the boiler heats the entire tank up to temp, then stops heating (except for radiators) then problem is NOT scale, as the water (in the tank) is already at temp. Scale in the tank would only cause the water to take LONGER to heat up.
How much hot water are you drawing from the tank? If it's more than the amount of hot water stored in tank then that is why it going cold.
Some tanks have a enconomode setting/thermostat/switch which you can use to heat 1/3 the tank up (saving energy), but then you can only draw 1/3 of it's volume before it will runs cold. could be problem.
If it is scale then there are products which will remove it. I don't know if you can use them with hot water tank, nor how effective they are.
Regardless of the above the following questions should have been asked when figuring out which system is ideal for YOU.
How quick do you want hot water to fill a bath/sink etc.
How much hot water do you use in total.
(Baths vary but 80-100 litres common)
Combi boiler are limited to how fast water can be delivered to the taps and can take ages to fill baths, but the hot water is always available (less of a problem with boiler with higher rated outputs).
In SOME situations Combi boiler can save energy, because the water is only heated when needed, and It doesn't any time to cool down. BUT if the taps aren't used for some time the water in the pipes leading to taps can get cold, leading to people wasting water waiting for it to heat up. (very little heat is lost from a jacketed hot tank anyway, this is why airing cupboards don't work as well as they used to!)
If you have/want a power shower the hot water it uses cannot come from a Combi boiler. (they normally heat the water by electricity)
If a combi boiler breaks down you are left with no hot water and no central heating. It's a very small/cheap job to add an electric immersion heater to a hot tank just in case
You can, in the future, if you want, easily add solar water heating to a hot tank system, which I never heard being done with combi boiler. (I seen a solar water panel in the North of Scotland boil water, when it wasn't set up with enough flow through it!)
Parts can be bought as and when they are needed, and during repairs you can often keep central heating/hot water working while the other is fixed.
In general I'd work with what you already have. Why start completely from scratch if you don't need to. For you that's seems to be a system boiler/ hot-water tank.
for one bathroom,,, a combi
for two or more megaflow
youll end up a lot happier with a pressurized system
don't know about megaflow, so cannot comment.
but out of the other two go for conventional, which is what I have. Very pleased with it. My friend has combi and this was a big mistake.
Combi's are crap unless you shell out on a 40KW model.I wouldnt have one in my house thats for sure.
They have less length of life than a standard boiler because they have far more internal parts that a regular boiler.
Go for the megaflow or a ' range tribune' equivilent. Thats for the hot water cylinder. Oh and make sure that your installer takes a reading in incoming and working water mains pressure. Low pressure means the appliance will work but nowhere near its potential.
Boiler, Worcester Ri, or go for gold with a viessman.
Corgi is for gas only by the way. For a cylinder that you are thinking of you need somebody who is registered with BPEC to install and work on them.
Thats all.
Depending on your neck of the woods try to get somebody trading standards approved. We have that here is east sussex but its not rolled out to much of the rest of the uk.
Boiler change about £2,000. plus vat. All depends on your existing system though
Cylinder £1000 at least, maybe a bit more but they have sizes from 50 litre to 500 litre. £1K should get you a 175 or 200 litre model
PS, am all the above as well as IPHE and APHC.
Good luck
Have recently changed my conventional central heating system for a com-bi, advantages, gets rid of the clutter of cold water tanks, cylinder, separate pump etc. Also easier to maintain, cheaper to run, Eco friendly, no chalking up Only disadvantage some types only allow hot water to be drawn off one point at a time,once you get used to this the are OK'
combi cheapest option 1500 or2000 depending on boiler need insurance after warranty expires. megaflow much more costly but has advantage of equalibrium pressure when using more than 1 h/w tap
replacing it with new one is not necessary,all u need is servicing and maintenance ocassionally
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