The above is installed in a 5-bed house to 1996 regs in Northumberland ( no cavity wall insulation. 15 rads, all single convectors ). The house scored 90 on the SAPS test but design heat load in a dormer room over garage is way undervalued. By installing a rad 3 times original output, design temps are reached and by tuning some other rads to low temp or closing off same, boiler just about copes. As I believe that living areas are under-radded, worried that a condensor will not provide comforable temps in these areas due to original flow temp of 82 C which, I am told, cannot be supplied by any condensor ( max 75 C ). Advised that Vaillant SS is the best to install. Boiler does DHW and there are about 6 TRV's fiited in rooms used part of the time. Can anyone comment on the optimum way to proceed, hopefully with existing rads ?
Replace Potterton Prima 50 B ( inst 1996 ) with a condensor
- Thread starter ExThornHeating
- Start date
I know it wouldn't condense, I was just telling the OP that condensers can have 82 degree flow temp.
Am I right in thinking that even when condensers are not in condensing mode they are still efficient. Although the idea is to keep them condensing as much as possible.
Am I right in thinking that even when condensers are not in condensing mode they are still efficient. Although the idea is to keep them condensing as much as possible.
This is the OP. The 1st respondent's advice is probably about as near perfect as one can get. He has tackled the under-radding by proposing that insulation be added and this can be done. The Vaillant's weather controller, which modulates the burner, might well allow opitimum condensing in a situation of replacement into an existing CH system. I.E. hopefully the flow temp will only operate at near 82 C when there is severe weather. As I cannot be the first with this problem of not wishing to replace radiators, I hope to hear from someone who has met with this problem before and solved it by using a Vaillant ? Thanks to all.
I am sure that if a house has consistent insulation throughout, weather compensation will be well worth it.
With the VRC430 you cannot have more than one heating zone.
Vaillant boilers come delivered with a max 75 degree flow temp enabled, but this can be easily adjusted in diagnostic mode.
With the VRC430 you cannot have more than one heating zone.
Vaillant boilers come delivered with a max 75 degree flow temp enabled, but this can be easily adjusted in diagnostic mode.
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