Hive Mini & Blown Boiler PCB

[flameport]

I was told my current boiler will struggle to heat 2 showers & 12 radiators

Any combi boiler would supply heat to 12 radiators easily.
No combi will satisfactorily supply 2 showers simultaneously.

Also because it's now 11 years old.

Contrary to what some boiler slingers might claim, gas boilers do not self destruct after 10 years.

Also, I've ordered this hive which is for combi boilers:

It's the single channel version for combination boilers, so if you really want a battery powered affair to bang the boiler on and off at intervals with Centrica spyware included, then it's the correct choice.

 

[Madrab]

I was told my current boiler will struggle to heat 2 showers

It will struggle to run 2 HW outlets at the same time. As suggested, most combi's won't sustain 2 high powered showers at the same time. Even 2 HW outlets so even say 1 shower and someone turns on a HW tap downstairs, it will impact the shower.

Combi's are not advised for a busy households with multiple bathrooms unless some very clever water systems setup or everyone is prepared to work around their constraints.

 

[morqthana]

Is that a flow-rate issue?

Just thinking the biggest electric shower you can get is 10.8kW, and OK - they are not great, but they work. So a combi in the 30-40kW range ought to have 15-20kW available for each of two showers.

 

[DP]

Is that a flow-rate issue?

Just thinking the biggest electric shower you can get is 10.8kW, and OK - they are not great, but they work. So a combi in the 30-40kW range ought to have 15-20kW available for each of two showers.

Electric shower provides water at its dedicated shower head
Combi is connected to all the hot water outlets when more than one outlet run, that is when the fun starts.

 

[Madrab]

So a combi in the 30-40kW range ought to have 15-20kW available for each of two showers.

Doesn't work like that, wish it did.

It needs to be looked as - The mains will supply a given amount in dynamic pressure and flow - a 30Kw boiler will output a certain amount of HW @ L/min at a certain temp rise (35deg) - that would then need divided up between the 2 showers, so they would need to be regulated only to use that amount of HW in L/min. Couple that with how much mains water would actually available at that time and how cold that water is and how hot each person wants their shower and that's without anything else running in the house - washing machine, dishwasher, sinks etc. It all gets very complicated very quickly and doesn't stay consistent throughout the year. Very very difficult to control with all those variables.