Combi with two showers

[Knappers]

I've a customer who's keen on a combi to replace their existing regular boiler and copper cylinder, I've seen that worcester cdi's (and probably others) say suitable for 2 showers but I've still always advised against combi's with multiple showers.
How plausible is it and why wouldn't a similar sized 'si' or even 'I' do the job just as well?
Any experience here would be good.

Just for info, they currently have two remote control pumped showers and will be looking at changing for high pressure equivalents (mira do an appealing double shower unit)

 

[Burger]

Would this not all depend on pressure and available flow rates? Probably going to struggle imho.

 

[Knappers]

I can restrict flow on showers if needed but I've always persuaded customers to go unvented before.
It just seems to me that worcester are trying too hard to make up differences in their ranges.
Why is a cdi with a very similar flow rate more capable?

 

[Knappers]

Think I'm going for a baxi 636 (15l/m)with 8-10l/m restrictors on the showers (4-6l/m on taps if needed)...
?

 

[Harvest Fields]

I still wouldn’t fit a combi for 2 showers.

 

[ShaunCorbs]

Viessmann 222 what’s incoming flow and pressure

 

[Scott_D]

42 CDI or any other high output combi could run 2 showers if you have the incoming pressure and flie
If someone opens another tap though you have an issue