In coming water temperatures

[IanB1485]

@charlesdobson I take your point about the higher pressure pumps , but with the flow at the tap reduced, the pressure in the boiler will be higher and reduce the kettling effect . A shower takes less water per second so the pressure in the boiler remains high .Your posts are slightly confusing/contradictory - just to clarify
. the water temperature is poor at the taps , but OK at the shower in the colder weather OR the shower also struggles ?.
If the former then it definitely flow rate that is limiting the temperature, if the latter then there may be a fault with the boiler controls .
What model of Imass do you have as on one it mentions water from an 'onboard tank' which would provide a supply of 'prewarmed' water which could be an option to fit inside your caravan

 

[charlesdobson]

@charlesdobson I take your point about the higher pressure pumps , but with the flow at the tap reduced, the pressure in the boiler will be higher and reduce the kettling effect . A shower takes less water per second so the pressure in the boiler remains high .Your posts are slightly confusing/contradictory - just to clarify
. the water temperature is poor at the taps , but OK at the shower in the colder weather OR the shower also struggles ?.
If the former then it definitely flow rate that is limiting the temperature, if the latter then there may be a fault with the boiler controls .
What model of Imass do you have as on one it mentions water from an 'onboard tank' which would provide a supply of 'prewarmed' water which could be an option to fit inside your caravan

The quicker you run water over the boiler the less time it has to heat it , I have tried various pumps with the boiler and found the lower litres per minute works better with it , remembering that most caravans run on a fairly small bore pipework to start with which can be a restriction in itself, so the higher psi pump isn’t a benefit, it just constantly cuts in and out