by rosebery »
Wed Dec 30, 2009 6:51 pm
In this case we need to differentiate between:
a) the hot water takes a long time to get there although the pressure is fine and;
b) the water just comes out in a dribble whether its hot or cold.
Which one is it?
The former is a function of unlagged pipes and long pipe runs where no water has been drawn off for a while, and it sits in the pipe and looses temperature. Neither pumping it nor an unvented will change much in that respect.
The latter suggests that pumping it or an unvented at mains pressure might give you a better result. But your mains pressure MUST be adequate to support an unvented operation. Have you measured it?
You can fit an unvented that works only on its inbuilt immersion heater but they are expensive to run that way and it will take aeons to see a benefit to you in cost terms.
Cheers