I am replacing our old (30+ years) system boiler with a new combi (is the Worcester Bosch 35 Cdi a good choice?), but am a bit confused about what is the best way to flush the system: the tradional way with chemicals or a power flush? And if the latter, is it really necessary to flush each radiator and section of pipes separately?
Power flush or chemical flush ?
- Thread starter FrankL
- Start date
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Is this true? Are YOU replacing it? If you are, youare CORGI registered and with your experience you will know a bit about flushing. If you are not, you cannot replace it, and whoever fits it should discuss the flushing with you, as they will have to fill in the manfs guarantee card. Just check they actually flush it. Even with a powerflush it's not unheard of for people to do an ineffective job.
I would always recommend any combi, as they give service guys lots of work
Sorry, oilman, I meant to say that we are having the boiler replaced and no I do not know much about boilers, flushing, combi or not, etc. We had several installers visit us and they all seemed to think a non-condensing combi would be best (we recently moved into this old, big, stone built property with 5 bedrooms and 2 bathrooms). Reading this website makes me think a combi may not be the way to go though. Confusion also about the flushing because one installer said chemical flush is best, the other said power flush whole system at once, number 3 said power flush each radiator individually, and I don't know what to go for. We will have all radiator valves replaced (look ancient and some dont work), but the radiators can stay as they are not that old (don't know why the previous owners put new radiators in and kept the old valves). Any advice regarding choice of boiler and flushing would be greatly appreciated.
My view, for what it's worth, is if you do a powerflush, you do each one individually. There may be some confusion in the two statements about powerflushing in that first all valves are opened and the whole system is stirred up. Next all radiators have descaling chemical pushed through. Then all radiators but one are shut, and that radiator is flushed. This is repeated for each of the radiators in turn. Then the radiators are flushed with clean water, both directions, until the water runs clear, and again repeated for all radiators. Once this is finished, the acidity is checked and adjusted before finally adding corrosion inhibitor.
It may be your system is so clean, that a full flush is pointless. I have had one situation where this happened, and instead of a £350 exercise, I did it for £150 as it didn't justify any more.
Why are you replacing the boiler? You should have a good reason for this, and not just be told by some ******** that "it's on it's last legs", "it's not economic to repair", "it's inefficient".
I would even seriously look at oil as well as gas. I have a customer with a large 4 bed detatched house who used around £240 worth of oil last year, and they don't have the house cold. Oil boilers are inherently simpler and thus much more reliable than gas (look at the number of oil faults on the forum compared with gas, and even correct for the difference in total numbers in existence, and they're still better.
Be very careful about a combi, there is lots to read on the forum, and bear in mind they are NOT more efficient than other boilers and neither are condensing boilers in most cases. Despite what the government would have you believe. You also need an adequate water supply, has the installer checked it and told you the pressure and flow rate?
It may be your system is so clean, that a full flush is pointless. I have had one situation where this happened, and instead of a £350 exercise, I did it for £150 as it didn't justify any more.
Why are you replacing the boiler? You should have a good reason for this, and not just be told by some ******** that "it's on it's last legs", "it's not economic to repair", "it's inefficient".
I would even seriously look at oil as well as gas. I have a customer with a large 4 bed detatched house who used around £240 worth of oil last year, and they don't have the house cold. Oil boilers are inherently simpler and thus much more reliable than gas (look at the number of oil faults on the forum compared with gas, and even correct for the difference in total numbers in existence, and they're still better.
Be very careful about a combi, there is lots to read on the forum, and bear in mind they are NOT more efficient than other boilers and neither are condensing boilers in most cases. Despite what the government would have you believe. You also need an adequate water supply, has the installer checked it and told you the pressure and flow rate?
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Hope you don't mind me jumping on your post's FrankL,
Magnus Magnusson:"I've Started So I'll Finish".
Your name please ? Oilman
That's correct !
Your occupation ? Oil boiler specialist
That's correct !
You have 2 points,well done.The next 6 question will be hard,so good luck
What happen when condensing boiler eventfully became law,does this effect the oil boiler or are they going to be oil condensing boiler as well ?
What size oil tank would you say I would need (my side alley way is approx 800mm wide) for 12 radiators bearing in mind they're not all fully on which is control by trv's and are the tank gravity fed to the boiler or pump ?
Do I need building permission for tank storage ?
Can any plumber service oil boiler ? if not,are they easily available in the south-east area ?
Is it a question of just replacing the old boiler over in a gravity heating system ?
Can oil boiler be converted back to gas if need be incase of oil supply problem ?
Thank you,hope you have enjoy the show.
Mastermindoilman said:
Magnus Magnusson:"I've Started So I'll Finish".
Your name please ? Oilman
That's correct !
Your occupation ? Oil boiler specialist
That's correct !
You have 2 points,well done.The next 6 question will be hard,so good luck
What happen when condensing boiler eventfully became law,does this effect the oil boiler or are they going to be oil condensing boiler as well ?
What size oil tank would you say I would need (my side alley way is approx 800mm wide) for 12 radiators bearing in mind they're not all fully on which is control by trv's and are the tank gravity fed to the boiler or pump ?
Do I need building permission for tank storage ?
Can any plumber service oil boiler ? if not,are they easily available in the south-east area ?
Is it a question of just replacing the old boiler over in a gravity heating system ?
Can oil boiler be converted back to gas if need be incase of oil supply problem ?
Thank you,hope you have enjoy the show.
Frank. I mostly fit combis. But NEVER would I advise fitting one for a house with two bathrooms. Two PEOPLE is about the limit. Anyone who accepts a combi in a bigger household is putting up with its inadequacies.
Do you know what heating output you need? the better (usually German) condensing boilers, which will save you on bills and have been around a long time. Not as expensive as they were.
If you can afford it, look at an unvented hot water store. Assuming you have a good mains supply you then dont need shower pumps cos the hot is high pressure. That will cost towards £2k though.
Flushing - assuming you have/hd a vented system to now, it is likely to be sludgy. New rads may have been needed because of rust. Running some water from a drain point will give some idea - is it clear? I would power flush it. As said above, sometimes it becomes clear that the system doesn't need it badly it so it all takes a lot less time.
Do you know what heating output you need? the better (usually German) condensing boilers, which will save you on bills and have been around a long time. Not as expensive as they were.
If you can afford it, look at an unvented hot water store. Assuming you have a good mains supply you then dont need shower pumps cos the hot is high pressure. That will cost towards £2k though.
Flushing - assuming you have/hd a vented system to now, it is likely to be sludgy. New rads may have been needed because of rust. Running some water from a drain point will give some idea - is it clear? I would power flush it. As said above, sometimes it becomes clear that the system doesn't need it badly it so it all takes a lot less time.
oilman said:
Consider oil?
Come on, oilman; this is blatant bias on your part...
But on a serious note, you may find that the super-reliability suggested by oilman, is in fact offset by the super-bloodsucking cost of oil compared to gas.
And when I say bloodsucking, I'm serious; you might as well fill the oil tank up with blood, because that's what the oil supplier will want from you...
You will find that the only people with oil tend to be the ones who do not have access to gas (i.e. if they live out in the sticks).
Where I live, the council houses were built in the early 70's. Not in my house, but in some a couple of miles away, they installed oil boilers. Shortly after (mid 70's), as we all know, oil suppiers wanted a cut of meat off your body for oil, and so people forced the council to chage the boilers to gas because oil is so expensive compared to gas.
Masona, are you just taking the mick? if so I won't waste time replying.
Sterose wrote:
And these costs are?
I said in my post "...look at oil as well as gas.....". I didn't make a load of emotional statements which do nothing to support a reasoned argument
Sterose wrote:
And these costs are?
I said in my post "...look at oil as well as gas.....". I didn't make a load of emotional statements which do nothing to support a reasoned argument
oilman said:Masona, are you just taking the mick? if so I won't waste time replying.
Sterose wrote:
And these costs are?
I said in my post "...look at oil as well as gas.....". I didn't make a load of emotional statements which do nothing to support a reasoned argument
OK, oilman. I was just 'taking the mick' (because youre name is oilman, and you 'suggested' people look at oil aswell as gas).
But still, compared to gas, oil is not as cheap.
No,I'm notoilman said:Masona, are you just taking the mick? if so I won't waste time replying.
I just want to get a overall picture of what really is involved as I work in the oil refinery we might be getting discount on heating oil,so I'm not sure if it pay me to change over to oil depending on the costs layout.
Maybe not but the running costs of oil properly outweigh the gas ????????sterose said:
Yes, they all have to be condensing, very economical, only about 6 to 10 year pay back for the extra cost.
1200 litres is about the smallest, but lots of people are ok with this, and fill up twice a year. 12 seems a lot of radiators to have in an alley way
The oil can be run in flow and return pipes so the oil can go up hill as well. Some boilers specify it's ok to lift oil 2.5m just on the pump.
If you put it in yourself, yes. Or you could get an OFTEC registered guy to do it.
Well they could legally, but I'm sorry to say that even the OFTEC guys are a mixture just like CORGI guys. Some are good, some aren't, but they CAN do it in half an hour.
No, 'cos if you replace a boiler you're supposed to make it fully pumped.
If you have the space, you could have both boilers connected to the system and run which one suits.
I doubt it would be economic to change from gas, unless you are getting the oil for free, as it will cost £1000 to £2000 to set up for oil and even then you would be 5 to 10 years recovering the cost.[/quote]
Thanks for all the replies.
I will stick with gas as installing an oil tank sounds like too much hassle(and unnecessary cost, it's ugly, and the hassle of filling it up twice a year to name a few drawbacks).
Oilman, thanks for your explanation of chemical flush versus power flush; will go for the latter as the system is quite old.
Still not so sure about combi or not, but as the wife wants to get rid of 'all those tanks' in the bathroom it will probably be a combi. Also the second bathroom isn't really a bathroom as it contains just an electric shower, so I guess a combi will suit our requirements just fine.
I will stick with gas as installing an oil tank sounds like too much hassle(and unnecessary cost, it's ugly, and the hassle of filling it up twice a year to name a few drawbacks).
Oilman, thanks for your explanation of chemical flush versus power flush; will go for the latter as the system is quite old.
Still not so sure about combi or not, but as the wife wants to get rid of 'all those tanks' in the bathroom it will probably be a combi. Also the second bathroom isn't really a bathroom as it contains just an electric shower, so I guess a combi will suit our requirements just fine.
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