Well this has helped me make a decision. 
I have toyed with getting a fitted diesel heated 
system. But you can keep it. 
I have tried the gas boiler ( always felt risky) and had the immersion heater fitted in my delivery tank ( professionally on a 16amp RCD job) in my last house. 
For simplicity, safety, cost and a few other benefits 
I will be rigging the immersion heater up again.  

T