- Messages
- 6
Hi all.
I recently upgraded our CH system, but rather than the expected drop in gas consumption, Octopus is saying we're using roughly 30% more! The installer has said they can downrate the boiler, but to my mind that addresses maximum consumption, not any inefficiencies there may be relating to the install itself.
In nutshell, the system has gone from a 20yr+ Baxi back-boiler (15kW), no TRVs, and 13 rads producing ~25k BTU; to a Greenstar 8000 Life (30kW), TRVs throughout, and 12 rads producing ~43k BTU.
I know that a 15kW boiler running at full tilt will consume less gas than a 30kW boiler, and whilst the rads are all more efficient, they are also larger (most went from single to P+). But I thought the increased efficiencies (a condensing combi that modulates, better rads, TRVs) would offset that. Did I have unreasonable expectations? I'd really appreciate some advice from more experienced heads!
Not sure if it's relevant, but worth noting that it takes an hour to raise the room temps by 2 degrees (to 18). It's an old house though - 1930s, 4 bed detached, EPC E - so I'd expect poor performance in that regard.
I recently upgraded our CH system, but rather than the expected drop in gas consumption, Octopus is saying we're using roughly 30% more! The installer has said they can downrate the boiler, but to my mind that addresses maximum consumption, not any inefficiencies there may be relating to the install itself.
In nutshell, the system has gone from a 20yr+ Baxi back-boiler (15kW), no TRVs, and 13 rads producing ~25k BTU; to a Greenstar 8000 Life (30kW), TRVs throughout, and 12 rads producing ~43k BTU.
I know that a 15kW boiler running at full tilt will consume less gas than a 30kW boiler, and whilst the rads are all more efficient, they are also larger (most went from single to P+). But I thought the increased efficiencies (a condensing combi that modulates, better rads, TRVs) would offset that. Did I have unreasonable expectations? I'd really appreciate some advice from more experienced heads!
Not sure if it's relevant, but worth noting that it takes an hour to raise the room temps by 2 degrees (to 18). It's an old house though - 1930s, 4 bed detached, EPC E - so I'd expect poor performance in that regard.
