Repair or replace old combi boiler

I've got a 15 year-old non-condensing combi boiler in a 2-bed semi, which has developed a controller fault.

I can replace the PCB or replace the boiler. If it was a condensing boiler, I'd replace it. But I'm wondering if replacing a non-condensing with condensing will cause additional work.

Obviously, I'll need to add a condensate pipe. But it's in the kitchen, so I expect that won't be too difficult.

But I believe the CH water temperature will be lower, so might I need to re-size the rads? Is this something that can be worked out with a rule of thumb, or is it generally not a problem? Is it possible to run with the water temperature at the same temperature as the old boiler and accept that it won't actually condense?

Reply to
Caecilius
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It does not have to be lower (you can set it to whatever you like basically), however you get higher efficiency gains if you can keep the

*return* temperature low ish (you see most boost with the return below 54 degrees). You may be able to achieve that with balancing alone.

Yup, that is an option. You may well find that a modern boiler will modulate anyway, and be able to condense much of the year as it is. You may lose a little efficiency during the coldest months.

Reply to
John Rumm

standards change, so extra work may be required.

If using it on existing rads they should be well cleaned out & a magnetic cyclonic filter added.

NT

Reply to
tabbypurr

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