main mersey - water heater - says cannot be used on a shower system

[moony]

as title says, flow rate of 9 litres a minute of it with flow cup, but in back of mi's it says that the main mersey super is not to be used with shower systems ? but the medway and another one can. whats the reason for this and has anyone run a thermostatic shower off one and have they had any problems ? customer really does prefer a thermostatic and not electrical - but now we've read this not sure which action to take. baxi weren't much help couldn't explain why it shouldn't be used.

 

[mountainman]

The Mersey multipoint was the baby of the Mersey, Medway & Trent series and as such was a basic model with a much smaller diaphragm than the other two.
If you try running one on a thermostatic shower the variable water flow caused by the thermostat will cause the heater to go into an on/off cycle.

 

[moony]

thanks mountain man - much appreciated

 

[mountainman]

Your welcome 🙂