I've currently got an Ideal Icos HE18 heat-only boiler and, seemingly somewhat surprisingly given what I've read about it, has never let me down. However, at 15 years old I know it is only a matter of time before it reaches the end of its life and so I thought I'd start looking at candidate replacements that will fit within the current setup.
One boiler that caught my eye is the Intergas OV18, particularly due to its Opentherm support. I was wondering about pump overrun though as I see from the installation instructions that is appears to require it (set by default to 1 minute after demand) however the example wiring schematics (on page 52) appear to suggest that the pump doesn't have to be connected directly to the boiler but can instead be connected to the switched lived in the wiring centre. However, if wired this way how would the pump overrun be achieved, given that at the end of a demand from a zone valve the boiler would have no means to overrun the pump?
On an unrelated subject, can the OV18 be used on a sealed system? The instructions only discuss open vent but I note the specs say it can work up to 2.5 bar.
P.S. Are there any Intergas installers here that cover the Wiltshire/South Gloucestershire area? I've always figured that anyone interesting enough to discuss boilers and heating systems outside of the day job is probably exactly the sort of person I'd want fitting a new boiler for me!
One boiler that caught my eye is the Intergas OV18, particularly due to its Opentherm support. I was wondering about pump overrun though as I see from the installation instructions that is appears to require it (set by default to 1 minute after demand) however the example wiring schematics (on page 52) appear to suggest that the pump doesn't have to be connected directly to the boiler but can instead be connected to the switched lived in the wiring centre. However, if wired this way how would the pump overrun be achieved, given that at the end of a demand from a zone valve the boiler would have no means to overrun the pump?
On an unrelated subject, can the OV18 be used on a sealed system? The instructions only discuss open vent but I note the specs say it can work up to 2.5 bar.
P.S. Are there any Intergas installers here that cover the Wiltshire/South Gloucestershire area? I've always figured that anyone interesting enough to discuss boilers and heating systems outside of the day job is probably exactly the sort of person I'd want fitting a new boiler for me!
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