As you can probably tell, I know next to nothing about plumbing, DHW systems etc, so apologies in advance...
I think I have a conventional indirect CH and hot water system - ie gas boiler heats primary water source which is pumped through a coil in the water tank thus heating the secondary water source and feeding the primary water through the CH system of radiators around the house.
The hot water has an electrical "top up" system on the tank in the attic. This appears to be jacketed heating element in the tank which has no thermostat. There is an on-off switch (but no timer) to the supply. There is no thermal cut-out built in.
Emerging from the tank is a pipe which has a TRV fitted. I presume this controls the water heat (or flow?) to the CH system? To be honest I'm not really sure what this does, and would be grateful if someone could clarify it for me or link to somewhere on the web.
The problem I have is that it seems to take a long time to heat up the hot water for a bath, and it is not that hot when it runs. I have re- lagged the tank recently, and this seems to have made a difference in that I can hear the water in the tank getting hotter quicker and bubbling away. The pipes certainly seem hot enough, but when I run the taps the water comes out lukewarm.
I presumed that using the gas boiler to heat the water in the tank would be best and then topping up the heat via the electric water heater would offer the most efficient and/or economic means of getting the hottest water at the least expense.
But how would this be affected by the setting on the TRV of the pipe emerging from the tank? What does it do and what setting would be best?
I presumed that if I turned off the radiators or had them set low that this would result in the water circulating through the pipes at a higher temperature and hence there being more heat for the DHW. Is this right?
What about the radiator in the bathroom? I have read that this should always be on max. Is this right? If it isn't on max, will this affect the water temperature?
Sorry for the all the questions. Any help or understanding you could give me would be great. At the moment I'm adjusting various things based on little more than guesstimates and (unsurprisingly) this approach hasn't worked.
Many thanks for reading this far and for any help, insight or advice you are able to give.