Boilers and water heating
Discussion
What's the name of those new boilers that don't need a hot water cylinder, but heat the water on demand?
I'm thinking of changing my system to a pressurised one and this seems like a way to avoid needing a pressurised hot water tank. I can then bypass the cold water tank and bingo - pressurised hot and cold!
(I would go and ask my local friendly plumber's outfit but have to stay in to wait for a courier...)
I'm thinking of changing my system to a pressurised one and this seems like a way to avoid needing a pressurised hot water tank. I can then bypass the cold water tank and bingo - pressurised hot and cold!
(I would go and ask my local friendly plumber's outfit but have to stay in to wait for a courier...)
moosepig said:
Combination boilers. They're the dogs' danglies! 
Thanks! Now I know what to search for, I found this: www.diyfaq.org.uk/plumbing/combi.html
Should keep me busy for a bit!
jmorgan said:
Aye, combination. But aren't condensing boilers better?
Different part of the boiler. Combination refers to the fact that the boiler does heating and DHW on the same heat exchanger; condensing refers to the efficient re-use of hot exhaust gases to further heat water (and condensing the hot water vapour out of the fumes as part of that process).
As of last month all new-fit boilers now have to be condensing, whether they're combination or not.
>> Edited by moosepig on Thursday 26th May 10:31
moosepig said:
As of last month all new-fit boilers now have to be condensing, whether they're combination or not.
Not quite true. There are situations where it is deemed impossible to fit a condenser and in these situations you can get exemption.
As for Combination Boilers Simpo, be aware of the poor flow of water that most will produce. 15 litres/ minute is fairly good for a Combi boiler, filling a bath can be frustrating although showers are fine of course.
moosepig said:
Aye, combination. But aren't condensing boilers better?
Different part of the boiler. Combination refers to the fact that the boiler does heating and DHW on the same heat exchanger; condensing refers to the efficient re-use of hot exhaust gases to further heat water (and condensing the hot water vapour out of the fumes as part of that process).
As of last month all new-fit boilers now have to be condensing, whether they're combination or not.
>> Edited by moosepig on Thursday 26th May 10:31
Ta.
I've just had a visit from a friend whose house has a combi boiler. He reckons they are unecessarily complicated, expensive to service/repair, and advises me to stick with what I have, the adage being 'keep it simple'.
So as my only need for high pressure is for the bath, the simplest/cheapest option is a 'whole house' pump (shower pumps not suitable apparently) which I can mount underneath. If it's really noisy and horrible I can sell it on eBay and go for a pressurised HW cylinder instead.
So as my only need for high pressure is for the bath, the simplest/cheapest option is a 'whole house' pump (shower pumps not suitable apparently) which I can mount underneath. If it's really noisy and horrible I can sell it on eBay and go for a pressurised HW cylinder instead.
simpo two said:
I've just had a visit from a friend whose house has a combi boiler. He reckons they are unecessarily complicated, expensive to service/repair, and advises me to stick with what I have, the adage being 'keep it simple'.
Had one in our old house, new. In nearly nine years it needed a fix just once, produced hot water whenever we needed it and didn't waste fuel when we didn't. Because the system is closed, we got our showers at mains pressure (I hate pathetic drippy showers), and bath filling was about the same as a normal system.
Just out of interest, what house pump did they suggest. I have one in my house on the hot water (from the cylinder) and it turns out it is only rated up to 35 Celcius. I expect the seals to be be giving up soon, so I am thinking of replacing it.
It is a very good solution (much cheaper than a pressurised system) and it means all the mixer taps/shower in the house actually work with similar hot/cot pressure. the bath fills up damn quick too.
TIA
Sparks
>> Edited by Sparks on Thursday 26th May 12:07
It is a very good solution (much cheaper than a pressurised system) and it means all the mixer taps/shower in the house actually work with similar hot/cot pressure. the bath fills up damn quick too.
TIA
Sparks
>> Edited by Sparks on Thursday 26th May 12:07
Sparks said:
Just out of interest, what house pump did they suggest. I have one in my house on the hot water (from the cylinder) and it turns out it is only rated up to 35 Celcius. I expect the seals to be be giving up soon, so I am thinking of replacing it.
They recommended the Salamander 'Right Whole House Pump', which comes in three capacities. Spec says max temp 60-65C.
sales@showerpumps.co.uk
01234 355515
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=57212&item=4384314727&rd=1
>> Edited by simpo two on Thursday 26th May 12:27
Although I have enormous respect for Salamander they are much less 'forgiving' in their 'allowed' pipework configurations. Bear in mind if you don't follow their installation instructions to the letter they will not be interested in warranty claims.
Having said that you may not have a problem, but be careful what method you use to connect it to the hot-water cylinder.
As far as Unvented hot goes, it's got to be the best solution with so little to go wrong, but retro-fit installation can be difficult with regard to discharge pipes etc and with a cylinder costing £500 it can be a bit dear.
Having said that you may not have a problem, but be careful what method you use to connect it to the hot-water cylinder.
As far as Unvented hot goes, it's got to be the best solution with so little to go wrong, but retro-fit installation can be difficult with regard to discharge pipes etc and with a cylinder costing £500 it can be a bit dear.
Ferg said:
As far as Unvented hot goes, it's got to be the best solution with so little to go wrong, but retro-fit installation can be difficult with regard to discharge pipes etc and with a cylinder costing £500 it can be a bit dear.
Thahks Ferg, I'm open to suggestions if you have a better option than Salamander.
I'm guessing 'unvented hot' means pressurised cylinder? I think I'll try a pump first, and if it vibrates the house to bits, I can sell it and go for the cylinder option.
Thanks for the input!
simpo two said:
Just out of interest, what house pump did they suggest. I have one in my house on the hot water (from the cylinder) and it turns out it is only rated up to 35 Celcius. I expect the seals to be be giving up soon, so I am thinking of replacing it.
They recommended the Salamander 'Right Whole House Pump', which comes in three capacities. Spec says max temp 60-65C.
sales@showerpumps.co.uk
01234 355515
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=57212&item=4384314727&rd=1
>> Edited by simpo two on Thursday 26th May 12:27
Thanks, I will take a look.
Sparks
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