Replacing old regular boiler

[Sprint]

Hi

I seek some advice on replacing an existing regular boiler.

I currently have an old Potterton 10-16 Netaheat electronic, which is around 35 years old and still working OK. It is fitted to a std 'Y' plan system with boiler in utility room and separate hot water tank, pump, valve etc in upstairs airing cupboard.

I would just like to do a direct replacement with another regular boiler such as a Worcester Bosch Greenstar 15Ri.

However, I find that any new boiler requires the pump to be directly connected to the boiler to allow for the pump overrun ability.

Consequently, as I have been advised, this will require getting wire(s) form the boiler to the pump in the airing cupboard. Unfortunately there does not appear to be any spare wires available and whilst not impossible getting wires form the utility room to the airing cupboard would be extremely difficult, unless some of the existing wiring can be re-configured, which I doubt.

So what is/are the solutions?

I understand that there are Mainslink pro's or similar, that can allow one to remotely connect the boiler and pump together, are they any good and a possible solution, or can I use a system boiler such as the Worcester Bosch 4000 15Kw with a vented hot water tank and if so what would this entail?

The pump would then be integrated with the boiler, but can I retain the existing expansion tank in the loft or do you have to use the one in the boiler?

Does it also require that you have the boiler supplied with a separate mains fed water supply or can it be fed from the cold water tank in the loft?

Would appreciate some advise/suggestions.

Thanks

 

[ShaunCorbs]

Go for one with a stainless heat exchanger then you don’t need a pump overrun or you might have a spare wire / core that you can use etc

 

[gmartine]

Seal the system, get rid of F/E tank and put the pump near to boiler/controller.

 

[Sprint]

Thanks for the replies. At this moment in time I would like to retain the existing system set up and part locations and just replace the boiler and maintain the vented tank, hence my questions relating to that.

You have referred to one with a st/st heat exchanger? I thought that all heat exchangers are st/st? Unfortunately, as indicated there does not appear to be any spare wires that can be used, unless one or more of the existing wires can be reconfigured, which is something I am not able to identify.

So are Mainslinks or similar a possibility or can I use a system boiler as a direct replacement?

 

[ShaunCorbs]

Thanks for the replies. At this moment in time I would like to retain the existing system set up and part locations and just replace the boiler and maintain the vented tank, hence my questions relating to that.

You have referred to one with a st/st heat exchanger? I thought that all heat exchangers are st/st? Unfortunately, as indicated there does not appear to be any spare wires that can be used, unless one or more of the existing wires can be reconfigured, which is something I am not able to identify.

So are Mainslinks or similar a possibility or can I use a system boiler as a direct replacement?

Alum heat exchangers require a pump overrun to save stress on the alu castings

Stainless doesn’t suffer from this / not required

You could run a timer relay eg when switch live is lost it runs the pump for 5 mins etc you wouldn’t need anything but a timerdelay relay and an enclosure if you wanted a alum hex eg Worcester etc

 

[Sprint]

Thanks for reply.

Understand, thought that all heat exchanges were st/st, clearly not and I assume WB ones are not, hence the pump overrun requirement? I understand that some of the Baxi boilers don't need POR so they must be st/st?

I see that Salus do an affordable GGPC1 RF pump switch, which may be the simplest option, cant attaché link.

Would prefer to go the WB route but I guess a lot depends on what they allow to maintain the guarantee but from what I have seen there does not seem to be any spare wires available.

 

[ShaunCorbs]

I suspect your issue would be the guarantee also would avoid salus they don’t have the best signal strength

 

[Sprint]

There must be many installations that are in my position where laying extra wiring to accommodate the requirement of pump overrun is not possible/practicable so what are the formal solutions? Thanks for the advice on the Salus, what is a better alternative?