Hello again all
Thanks for your great advice on my previous post.
After much deliberation with OH (and unexpected PW surveyor costs), we've had to forego the Vitodens condensing boiler, and have decided to go for one of Vaillant ones
We currently have (I think) a traditional open vented system, ie. boiler in kitchen, HWC in bedroom with small (feeder?) tank in same airing cupboard, plus tank in the loft. I've no idea of the btu/kw of the HWC, but it measures approx 38cm diameter and 101cm height (incl domed section at top). We have a 3bed mid terr, and will have 9 radiators once rear extension is completed. There will be an upstairs bath/shower, downstairs power shower (with pump), plus usual kitchen appliances. The plumber has suggested increasing the size of the HWC and putting in an expansion vessel. We currently have a CH thermostat in the hallway, and a HW/CH timer/programmer in the airing cupboard with the HWC.
Our favoured boiler is the Vaillant ecoMax condensing boiler (NOT the combi), mainly because of the S/S heat exchanger, which the Worcester-Bosch Greenstar doesn't have.
We need to buy the boiler and the flue, so I've been trying to do some research so that I know what questions to ask the plumber when we see him again, but I just seem to be getting myself all confused
My questions are:
(a) which type would be best suited to us - the ecoMax 618/2E or 622/2E http://uk.vaillant.com/folder.php?f...-10330-10333&folder_default_netfolderID=10333 , or the ecoMax pro 18E or 28E http://uk.vaillant.com/folder.php?f...-10330-10473&folder_default_netfolderID=10473? (Is the ecoMax pro actually a combi? )
(b) how important is the CH output range? The 618/2E says 11-18.4 at 80/60 deg flow/return, and the Pro 18E says 5-18.3. Is this what is called the modulating range? And is it a case of the lower the low temperature, the better (efficiency wise)?
(c) is the weather compensator http://uk.vaillant.com/folder.php?f...-10332-10490&folder_default_netfolderID=10490 suitable for the 618 or the 18E? On the Vaillant website, all the other controls seem to be for combis only.
(d) There are various types of flue available, so we need to check with the plumber which one to buy. (The pipes from the HWC are staying where they are, but boiler is going on the rear external wall of the extension). What other questions do you recommend we ask him?
(e) The plumber recommended we buy the 18kw size, because he was concerned that we may have 'stale water' if we don't use up all the water in the cylinder. Is this something to be concerned about? (It's not as though we'd be drinking it!) Would it be better to go to the 22 or 28kw size?
As always, I'd appreciate your comments on any of the above.
Thanks again
Thanks for your great advice on my previous post.
After much deliberation with OH (and unexpected PW surveyor costs), we've had to forego the Vitodens condensing boiler, and have decided to go for one of Vaillant ones
We currently have (I think) a traditional open vented system, ie. boiler in kitchen, HWC in bedroom with small (feeder?) tank in same airing cupboard, plus tank in the loft. I've no idea of the btu/kw of the HWC, but it measures approx 38cm diameter and 101cm height (incl domed section at top). We have a 3bed mid terr, and will have 9 radiators once rear extension is completed. There will be an upstairs bath/shower, downstairs power shower (with pump), plus usual kitchen appliances. The plumber has suggested increasing the size of the HWC and putting in an expansion vessel. We currently have a CH thermostat in the hallway, and a HW/CH timer/programmer in the airing cupboard with the HWC.
Our favoured boiler is the Vaillant ecoMax condensing boiler (NOT the combi), mainly because of the S/S heat exchanger, which the Worcester-Bosch Greenstar doesn't have.
We need to buy the boiler and the flue, so I've been trying to do some research so that I know what questions to ask the plumber when we see him again, but I just seem to be getting myself all confused
My questions are:
(a) which type would be best suited to us - the ecoMax 618/2E or 622/2E http://uk.vaillant.com/folder.php?f...-10330-10333&folder_default_netfolderID=10333 , or the ecoMax pro 18E or 28E http://uk.vaillant.com/folder.php?f...-10330-10473&folder_default_netfolderID=10473? (Is the ecoMax pro actually a combi?
)(b) how important is the CH output range? The 618/2E says 11-18.4 at 80/60 deg flow/return, and the Pro 18E says 5-18.3. Is this what is called the modulating range? And is it a case of the lower the low temperature, the better (efficiency wise)?
(c) is the weather compensator http://uk.vaillant.com/folder.php?f...-10332-10490&folder_default_netfolderID=10490 suitable for the 618 or the 18E? On the Vaillant website, all the other controls seem to be for combis only.
(d) There are various types of flue available, so we need to check with the plumber which one to buy. (The pipes from the HWC are staying where they are, but boiler is going on the rear external wall of the extension). What other questions do you recommend we ask him?
(e) The plumber recommended we buy the 18kw size, because he was concerned that we may have 'stale water' if we don't use up all the water in the cylinder. Is this something to be concerned about? (It's not as though we'd be drinking it!) Would it be better to go to the 22 or 28kw size?
As always, I'd appreciate your comments on any of the above.
Thanks again