New Boiler (& shower pump?) - what do I need to consider

[astiling]

I'm about to start the process of renovating some bathrooms in my house (3 bed bungalow with 2.5 bathrooms and about 12 radiators). Before changing the bathrooms I think I should also change the boiler - our current one is noisy and quite an old Potterton (NetaHeat?) model.

I was thinking of getting a combi boiler which would allow me to also extend one of the bathrooms into the space used by the emersion heater/airing cupboard. Some questions I have:

Is a combi appropriate for this size of house/number of bathrooms?

Considering primarily reliability and suitable for this size house - what makes/models would be recommended?

I assume hot water pressure will suffer when multiple hot water appliances (2 showers or 1 shower + washing machine) are used - is this correct, to what extent/how can I reduce the impact of this?

Is shower pressure good (i.e., will it be similar to a power shower) from a combi? What other factors might affect this that I can control to increase shower pressure? I've been told you can't pump water exiting from a combi but can pump water from a cold water tank to the combi which may help with shower pressure - correct/a good idea?

Is it a good idea to install a water softener before the water gets to the combi as I have quite hard water?

If I need to keep an emersion heater, is there any reason why this can't be put in my loft so I can still reuse the airing cupboard space?

I'm still a bit dazed by all the possibilities so any extra info is greatly appreciated.

I am planning to get some quotes/advice from heating engineers but wanted to be well prepared before consulting them.

Thanks
Adam

 

[BRENMONA]

I think you would regret installing a combination boiler because of limited hot water flow rates, and i wouldnt even consider them for more than 1 bathroom

Get your Engineer to put both your new boiler and an unvented unit like a megaflow up in your loft, water softeners are great, and well worth the initial investmen,

Your engineer should check to make sure you have adequate mains pressure and flow rate to enable unvented unit to work to full potential.

If you search for unvented or megaflow in search engines you should find plenty to read up on

 

[breezer]

i am not a plumber or heating engineer. we have 1 bathroom (poor us) if having shower, we dare not put on washing m/c as shower decides to trickle*, for us its not a problem for you i do not know (boiler is a combi)

* this is because incoming to house water is split between shower (1st floor) and washing m/c gnd floor. bit like two people want an orange and only one orange available, answer half each

 

[astiling]

Thanks for the suggestions - unvented tanks are new to me but this seems the ideal option + I'll save on the cost of pumps. If I understand correctly the unvented tank option means:

1) I can do away with the cold water tank and existing emersion tank completely
2) I buy (& get properly fitted!) a megaflow (or similar)
3) If I want I can also replace my existing boiler but I just need a regular boiler (not a combi) so I assume generally cheaper than a combi.
4) The unvented tank takes mains cold water and takes hot water from the boiler that it then stores until needed at an equivalent to mains pressure.

Some more questions though as I start to understand more:

Does the unvented tank use electricity to keep the hot water at the correct temp or does it re-cycle it back to the boiller?

What happens if all hot water in the unvented tank is used up?

Why does cold water go through the unvented tank (I think I read that it does...) as opposed to running the mains water to all cold water outlets?

If I go with an unvented option, how should I size the tank capacity? And what type of boiler should I go for - i.e., as the water is stored, is there much of an issue with boiler heating delivery?

Thanks again