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Upgrading an Old MCU After EICR , RCBO Installation Worth It?

Johnny Hotpot

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Apr 6, 2025
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Just got hit with an EICR report on a property I'm working on, came back as "unsatisfactory" mainly due to lack of RCD protection on a few circuits. The current MCU is an older split load unit, and I've been weighing up the options so, I'm seriously considering installing RCBOs instead of swapping the whole consumer unit. It seems like a neat solution that avoids the full rewire headache, especially since the board has space but, I've heard mixed things about compatibility with older MCUs and potential nuisance tripping?
Anyone here gone down the RCBO retrofit route? did it solve the EICR issues cleanly, or would you just go all in and replace the board entirely? appreciate any tips, especially from those who've tackled this in real world jobs.
 
I've never tackled with this job before but i think that it's a good idea to retrofit rsbos into an older split-load consumer unit can fix eicr issues without a full rewire, especially if there's space. Just don't forget about compatibility and nuisance tripping with older boards. If the mcu is outdated, then maybe it's better to replace the whole unit.
 
I've retrofitted RCBOs on older boards, they worked out fine and cleared EICR issues without drama, be on the look out for brand comaptiibility,its way easier than a full board swap if everything else is good.
 
Just make sure the board is in good shape, meaning it doesn't sho signs of age like heat damage, cracked case, stuff like that. If that's the case, I'd replace it entirely
 
Just got hit with an EICR report on a property I'm working on, came back as "unsatisfactory" mainly due to lack of RCD protection on a few circuits. The current MCU is an older split load unit, and I've been weighing up the options so, I'm seriously considering installing RCBOs instead of swapping the whole consumer unit. It seems like a neat solution that avoids the full rewire headache, especially since the board has space but, I've heard mixed things about compatibility with older MCUs and potential nuisance tripping?
Anyone here gone down the RCBO retrofit route? did it solve the EICR issues cleanly, or would you just go all in and replace the board entirely? appreciate any tips, especially from those who've tackled this in real world jobs.
Had the same experience with @Stanstan here. Adding a tip that you gotta make sure the brand and form factor match or you'll be fighting fit issues.
 
you should have the IR values for each circuit on the EICR report, do they all look ok? When you say a split load board do you mean some circuits on an RCD & some on just a main switch, or Main switch & then the circuits split over 2 RCDs?
 
Just got hit with an EICR report on a property I'm working on, came back as "unsatisfactory" mainly due to lack of RCD protection on a few circuits. The current MCU is an older split load unit, and I've been weighing up the options so, I'm seriously considering installing RCBOs instead of swapping the whole consumer unit. It seems like a neat solution that avoids the full rewire headache, especially since the board has space but, I've heard mixed things about compatibility with older MCUs and potential nuisance tripping?
Anyone here gone down the RCBO retrofit route? did it solve the EICR issues cleanly, or would you just go all in and replace the board entirely? appreciate any tips, especially from those who've tackled this in real world jobs.
I've done a few RCBO retrofits on older split-loads and they passed EICRs just fine. Like others said, brand compatibility is important. Please don't mix and match.
 
Just got hit with an EICR report on a property I'm working on, came back as "unsatisfactory" mainly due to lack of RCD protection on a few circuits. The current MCU is an older split load unit, and I've been weighing up the options so, I'm seriously considering installing RCBOs instead of swapping the whole consumer unit. It seems like a neat solution that avoids the full rewire headache, especially since the board has space but, I've heard mixed things about compatibility with older MCUs and potential nuisance tripping?
Anyone here gone down the RCBO retrofit route? did it solve the EICR issues cleanly, or would you just go all in and replace the board entirely? appreciate any tips, especially from those who've tackled this in real world jobs.
Been there, done that! RCBOs are a solid move for EICR issues, especially if you've got the panel space. Nuisance tripping can happen, but it's less common with quality RCBOs. Usually way cleaner than a full panel swap if the wiring's otherwise decent. Go for it, dude!
 
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