Radiator temp drop

[gaz1]

you still dont get it

when you have equaled both the rads first and then you equalised the cylinder then you can run both at the same time

its when the cylinder is sent direct path open it will cause the rads to stay cold similar to the rads that take the quickest run when just feeding the 4 rads via the first video

if you want the cylinder to warm first before you get up then you can do so using a dual timer one for central heating the other for the hot cylinder just have it on 1/2 hr before direct to rads for get up times in a morning twice daily is normally enough for a well insulated cylinder 3/4of an hr being the optimum for a full tank of hot water

for those systems that are run both then with them being set equalised then you can run the system as normal rad and cylinder and the system will heat well enough during that time until the cylinder stat closes the valve to the cylinder

 

[gaz1]

check where the coil pipes are by the model of cylinder that you have only balance the cylinder whilst the rads are being run at the same time

make sure your not closing valves off that you shouldnt be touching

 

[JimmyS]

It's not that easy to get some of the hot water cylinders to work with a low return water temperature. They are notorious on district heating systems for causing the return water temp to elevate which they normally want to avoid. Often on commercial systems they will use a plate heat exchanger instead. With the cylinder I'd just throttle it back as best you can on the gate valve, which is not ideal for flow regulation but will hopefully be ok once you get it wound in sufficiently to give you reasonable heat output from the rads then it will heat the cylinder until its satisfied then the zone valve will close, and your rads will revert to the same conditions as your original balance.