Boiler Flow Temperature- vailiant eco tech plus 418

[kofi2003uk]

Hi Everyone
Need some advice please. I have a hot water cylinder and my system is unvented. Works fine but like a lot of people am trying to save on heating.
My question is can I turn the flow temperature down to 65? I believe it’s set at 75 from the factory. Am also aware that as I have a hot water cylinder ,I can’t turn the flow temperature too low.

What is the lowest safe temperature can I use then and keep the water in the cylinder safe too please?

Thanks all

 

[Mottie]

On my 418 EcoTEC plus, I run it at 62°. I also have it set at 15Kw (12Kw in summer when just heating the water). I have my 3 speed pump set on the lowest setting too. Takes a little longer for the rads to warm up from cold but haven’t noticed any difference in the hot water.

I believe if you have the Vaillant controls (on the boiler) you can run the heating and hot water at different temperatures. I don’t have Vaillant controls though.

 

[kofi2003uk]

Thanks Mottie. Sounds like you have a combi boiler?
Mine is not combi. Can’t separate hot water and heating on the boiler. I have a hot water cylinder, for storing hot water and that’s why I need to make sure the water is hot enough in cylinder to prevent legionnaires .

Thank for the reply. It’s appreciated

 

[Mottie]

Thanks Mottie. Sounds like you have a combo boiler?

No, a regular heat only boiler with a hot water cylinder like you have. As said, if you have the Vaillant controls (fits in a panel on the front of your boiler), you can set different heating and hot water flow temperatures.

 

[kofi2003uk]

I see. Will look into this.
Am also thinking I could set the thermostat on the hot water cylinder itself o 60 degrees and have the boiler at 65 or say 62 degrees .So at least the boiler can heat the hot water to 60 degrees, which I believe is safe.

Thank you

 

[Mottie]

I see. Will look into this.
Am also thinking I could set the thermostat on the hot water cylinder itself o 60 degrees and have the boiler at 65 or say 62 degrees .So at least the boiler can heat the hot water to 60 degrees, which I believe is safe.

Thank you

I have my thermostat on the cylinder set at about 45°. If it was set at 50° I'd scald myself. Set at 60, I don't think you’d get there. Don't forget, the thermostat is at the bottom and the hot water is at the top! Try it with yours BUT use a thermometer to see the actual temperature of the water coming out of the hot tap and adjust it accordingly (giving the boiler time to heat the hot water in the tank before testing again if not hot enough).