Our shower in our new house is not running hot. We have a Redring
PowerStream Eco 9.5kw - found in the loft. We understand this was put in to avoid the need to connect to the mains- combi boiler as it is on the third floor.
Plumber says scrap it and connect shower to mains. Redring say the mixer is allowing too much cold into the shower and a new manual mixer on the shower would fix it.
Is it worth the hassle of re-plumbing to the mains hot water to get a better shower ( its the less-used 'guest bathroom')
Also - the DIYer who put it in misconnected the toilet cistern so it is flushing with hot water so I'm not sure I trust the previous owners decisions!