New boiler - is it necessary? (replacing a 5yr old pro combi HE)

Cyclonicity

I'm currently renovating a 1960s semi - as part of the renovation it will need the fitting of several new radiators as well as the replacement of the majority of existing radiators (some are so old they are starting to corrode). There are 7 radiators in total, and I plan to have 9

The boiler is a 5 year old Pro combi HE - a fairly cheap one but still works OK (though the pipework to the boiler will need replacing). I am looking to move the boiler as well (currently by the front door - looking either to lift up to make space for a downstairs toilet, or move somewhere into the kitchen - the understairs cupboard already has gas and electric meters in). The boiler itself has never actually been serviced.

With that said, Is it worth replacing? It seems a bit wasteful changing a boiler that's only 5 years old, but maybe this is the best time to do it while the plumbing work is already underway? Is it a fairly simple job to replace just the boiler, if all the pipework and radiators are intact?

Any input appreciated!!

CashStrapped

I assume you are getting a gas safe registered engineer out to re-plumb everything. So why not ask their opinion. If it is servicable, then, why not. Not being serviced in 5 years is not great thoug, so it will need a thorough check over.

One issue would be that you are adding more radiators. So you need to check that the combi was actually correctly sized for the property in the first place (powerful enough) and that it would still be powerful enough after you update everything.You may find you need a more powerful one. Again, an engineer will know this.

You do not want an underpowered boiler as it would have to work at full pelt just to work normall. Think of it as having an small car engine in a sports car. This would not be good for your bills. Again, ask the engineer.

Cardew

CashStrapped wrote: »

I assume you are getting a gas safe registered engineer out to re-plumb everything. So why not ask their opinion. If it is servicable, then, why not. Not being serviced in 5 years is not great thoug, so it will need a thorough check over.

One issue would be that you are adding more radiators. So you need to check that the combi was actually correctly sized for the property in the first place (powerful enough) and that it would still be powerful enough after you update everything.You may find you need a more powerful one. Again, an engineer will know this.

You do not want an underpowered boiler as it would have to work at full pelt just to work normall. Think of it as having an small car engine in a sports car. This would not be good for your bills. Again, ask the engineer.

With a combi the power(output) is largely determined by the Domestic Hot Water(DHW) requirement and not the heating(radiator) load. So IMO adding two radiators would not be a problem.

CashStrapped

That may be true, but like I said, it may not have been specified properly to begin with, so it is always best to check.

I did think that multiple factors determine what boiler power output should be chosen. Even things such as insulation levels. I remember reading it somewhere. So I am sure that other things other than DHW requirement (which may be the main consideration) come into play when making the calculation.

But.....I am not a heating engineer....so I may be wrong...which is why the OP should ask the engineer when reconfiguring the existing system.