Efficiency of heating water tank along with rads in the middle of the day

MadMattDog

We have a gas powered boiler; Baxi Megaflow. The rads have their own piping and the hot water tank has it's own. When you turn on the hot water tank it sends the hot water across from the system the rads use to heat up the water tank to 65 degrees. This is according to my dad. It sounds right.

My dad keeps telling me every time I turn on the rads in the middle of the day that I should turn on the hot water tank because we are wasting gas not keeping the tank as hot as possible while the rads are going since they are connected. The tank will keep hot water hot over night if heated up the night before and again during the day if turned on in the morning.

I'm wondering if he is in fact right or is it inefficient to bother heating the tank at a time when no one is using it. The radiators come on in the morning and are on in the evening so we heat the water tank then. I turn them on during the day if I'm around because my room gets cold quickly without then(old house, stone walls). It's the during the day part that I'm wondering about.

Any help or tips would be appreciated.

K.Flyer

If an hour or so in the morning and the same in the evening provides you with all your hot water requirements for the day, then further heating of water that is not being used, only for it to cool down and go to waste, is costing you money.

Dtp1979

MadMattDog wrote: »

We have a gas powered boiler; Baxi Megaflow. The rads have their own piping and the hot water tank has it's own. When you turn on the hot water tank it sends the hot water across from the system the rads use to heat up the water tank to 65 degrees. This is according to my dad. It sounds right.

My dad keeps telling me every time I turn on the rads in the middle of the day that I should turn on the hot water tank because we are wasting gas not keeping the tank as hot as possible while the rads are going since they are connected. The tank will keep hot water hot over night if heated up the night before and again during the day if turned on in the morning.

I'm wondering if he is in fact right or is it inefficient to bother heating the tank at a time when no one is using it. The radiators come on in the morning and are on in the evening so we heat the water tank then. I turn them on during the day if I'm around because my room gets cold quickly without then(old house, stone walls). It's the during the day part that I'm wondering about.

Any help or tips would be appreciated.

Your dad is wrong I'm afraid. I'd try time it an hour before the hot water is most commonly used. See how you get on with that on a trial basis.
As for turning on the hot water tank to heat the rads, I've no idea what that means

MadMattDog

Thanks for the reply's.

K.Flyer wrote: »

If an hour or so in the morning and the same in the evening provides you with all your hot water requirements for the day, then further heating of water that is not being used, only for it to cool down and go to waste, is costing you money.

He thinks otherwise because "the same flame heats the one source of water which heats up both the rads and the water tank os if the rads are on the tank should be too". I need help wording an explanation why he's wrong.

Dtp1979 wrote: »

Your dad is wrong I'm afraid. I'd try time it an hour before the hot water is most commonly used. See how you get on with that on a trial basis.
As for turning on the hot water tank to heat the rads, I've no idea what that means

Can you explain why he's wrong? And that's what I suggested but he insists it's wasting gas to not heat the tank when the rads are on.

Oh and sorry. What I meant was; we have 2 buttons on the control box, 1 turns the rads on for 1 hour, the other heats the hot water tank for 1 hour. Apparently the pipe that heats the rads splits off and wraps around the hot water tank.

I think I've made a bit of a mess explaining how the system works.

Dtp1979

What uses more energy?
To heat half a kettle of water or to heat a full kettle?
Heating your hot water uses more gas. It's that's simple
Unless you have a huge demand for hot water then only heat as much as your gonna use

MadMattDog

Dtp1979 wrote: »

What uses more energy?
To heat half a kettle of water or to heat a full kettle?
Heating your hot water uses more gas. It's that's simple
Unless you have a huge demand for hot water then only heat as much as your gonna use

I tried that line of thinking. He just keeps coming back to the fact there isn't 2 separate sources of heating in the boiler so it should use the same amount of gas to heat both because the boiler is heating everything at once. Which, like you said, is that simple, it's more water to heat up so it has to burn more gas to heat. I understand it, I just need to make him understand it.

I don't exactly understand why the boiler says it's at 68 degrees, but we only heat the rads up to about 16-7 degrees. I understand the hot water tank has to heat up to over 65 for health reasons but I don't get why the boiler itself stays that hot. I think that might be part of his argument for it also. But again I do still understand, more water means more heat means more gas used, just not how it all come together.

Deregos.

Your dad must be 'Radiator man'.

Dtp1979

MadMattDog wrote: »

I tried that line of thinking. He just keeps coming back to the fact there isn't 2 separate sources of heating in the boiler so it should use the same amount of gas to heat both because the boiler is heating everything at once. Which, like you said, is that simple, it's more water to heat up so it has to burn more gas to heat. I understand it, I just need to make him understand it.

I don't exactly understand why the boiler says it's at 68 degrees, but we only heat the rads up to about 16-7 degrees. I understand the hot water tank has to heat up to over 65 for health reasons but I don't get why the boiler itself stays that hot. I think that might be part of his argument for it also. But again I do still understand, more water means more heat means more gas used, just not how it all come together.

Your radiators are far hotter than 16-17 degrees. You're talking about room temp.
If your dad can't understand that then leave him be. You set your own heating as advised by professionals who work in the field every day.

MadMattDog

Dtp1979 wrote: »

Your radiators are far hotter than 16-17 degrees. You're talking about room temp.
If your dad can't understand that then leave him be. You set your own heating as advised by professionals who work in the field every day.

We both understand that 16 is room temp and the rads are hotter. I worded it wrong. Once we get the timer sorted so it comes on automatically this should all be done with.

K.Flyer

Set your Hot Water timer to run for an hour, with the hour ending just before you reckon you will be using the hot wat water from the cylinder.
Over time, adjust the duration of "time on" down (or up) by 10 min increments until you find the minimum amount of time that is required to run the boiler to provide you with enough hot water that you need.

Regarding your fathers suggestion..
When making a cup of tea you should only fill the kettle with the amount of water required, boil it once and use it.
Not fill the kettle up to the top and then keep re-boiling the water all day until such time as you might need it.