Recommended checks before CU change

I’ve made a decision to quote this job competitively to try and win it, as I need the experience, plus it’s for my reassessment.  I can use it as a learning experience too.  I’ll factor in a few extra hours for any remedial works in the quote and if they’re not need I won’t charge for them. 


A couple more questions though:


Both gas & water were bonded albeit in 4/6mm², gas is a pretty easy job to replace as I can run the cable externally to the gas cupboard in the utility room, kitchen stop c*** on the other hand is a bit more difficult as the stop c*** backs on to the conservatory, but in the garage is a water pipe coming up through the concrete garage floor at the back and this is where the water has been bonded.  Would this water bonding be suitable for the whole water installation?


Are Lewden RCBO boards ok?  Found out today that the plumbcentre are selling both lewden & bg populated rcbo boards at brilliant prices.  


Do you have to use C type rcbo’s if there are fluorescent lights in use, or should you always use C type rcbo/mcb on lighting circuits?

I’ve made a decision to quote this job competitively to try and win it, as I need the experience, plus it’s for my reassessment.  I can use it as a learning experience too.  I’ll factor in a few extra hours for any remedial works in the quote and if they’re not need I won’t charge for them. 


A couple more questions though:


Both gas & water were bonded albeit in 4/6mm², gas is a pretty easy job to replace as I can run the cable externally to the gas cupboard in the utility room, kitchen stop c*** on the other hand is a bit more difficult as the stop c*** backs on to the conservatory, but in the garage is a water pipe coming up through the concrete garage floor at the back and this is where the water has been bonded.  Would this water bonding be suitable for the whole water installation?


Are Lewden RCBO boards ok?  Found out today that the plumbcentre are selling both lewden & bg populated rcbo boards at brilliant prices.  


Do you have to use C type rcbo’s if there are fluorescent lights in use, or should you always use C type rcbo/mcb on lighting circuits?