If you have a new account but are having problems posting or verifying your account, please email Niamh on [email protected] for help. Thanks :)
New AMA with a US police officer (he's back!). You can ask your questions here

Hot Water Advice (5 person house)

  • 27-05-2020 9:33am
    Registered Users Posts: 88 ✭✭✭ Anto318

    Hi All,

    I'm purchasing a house at the moment which was built in 2004. The house has a recently installed boiler (Ideal Logic Heat 24) but I have some questions that I hope you might be able to help with.

    I'm moving from a new property where we have solar panels and during the summer months we'd have constant hot water. In the new property we don't have the same options.

    There's 5 in our household with 2 adults and 3 teenagers so I'm concerned that in the new property our bills will go through the roof for hot water.

    We're planning on doing some upgrades to the house before we move it (cavity wall pumping, attic insulation etc) and we're planning on changing out the bathrooms. Currently the showers are fitted with electric showers.

    I'm looking for suggestions on what's the best approach with the upgrades. Would we install Solar PV with a diverter to a larger hot water tank (current tank is 200L) and replace the electric showers with mixer showers off the tank?

    Any advise you can give would be appreciated. As I'm going from hot water Apr-Sept for free in my current house I'm nervous of getting a real spike in bills once we move into the new home.

    Thanks in advance,


  • Registered Users Posts: 435 ✭✭ mike_2009

    Pity there isn't a combi boiler in place! Maybe a balance of electric and gas heated water and a larger tank? If the showers are short then the electric showers still have their place but if there are any girls then you might have to put timers on them!! I just swapped out an electric shower for a mira mode (it has a timer option in the app!) which pumps gravity fed water and takes hot water from the tank but I have short showers. We're topping up the tank (201l) with an Eddi diverter and have solar PV / Battery / off peak tarrif all working out fine currently.
    In your case you just need to have sufficient time to replenish the hot water tank - gas is still cheaper than electricity to heat water. You could fit a central inline electric water heater that will "top up" heat in the hot water supply if it drops off and it only uses sufficient electricity for the job - you already have the wiring so this might be an option?
    You just want insurance vs when the first person to take a shower uses ALL the hot water!!
    Solar PV and a battery would be great plus a way to divert excess to the immersion but it's likely to be too late for the morning showers. My Eddi can be set to manually boost at set times and I use this with off peak tarrif to ensure my tank is topped off every morning.
    There are thermal stores that can act at a bigger buffer to your main tank but where to put them?! And in a few years you won't need it?
    Tell the teens to use the garden hose out the back...?!

  • Registered Users Posts: 10,926 ✭✭✭✭ Calahonda52

    This is why water charges are such a good idea.
    Here we have " unlimited" hot water April to Sept so water is a free resource which it is not, it is a finite resource that also comes at a cost.
    Yes you will have a cost problem due to what seems like a deeply embedded culture of wasting both hot and cold water, the hot because it is there, the cold, to cool and replenish.
    So the solution is looking for cost effective ways to continue this high volume of HW usage.

    Its bit like get 10G windows to kill the sound of a noise land mower: you need to look at the demand side.

    You need to change the culture of behaviour
    One idea is to get a thermal store with a heat pump, use night rate and with a COP of 3....

    Given the usage you might need a 5,000 l one

    then use the gas to top it top to 60 every so often to kill Legionellas

  • Registered Users Posts: 4,104 ✭✭✭ greasepalm

    I have old solar panels on roof and handy in summer for heating water in bright sunlight,i did see a newer panel which looked like a refrigeration panel that worked 24 / 7 like this one.

    I would also have a backup shower like the electric one just in case