Eberspacher Radiator valves Advice

[P1PPA]

Hi, I am new to having an eberspacher diesal heating system. I have a radiator in each room of my new boat. There are two valves on each radiator, a flow and return presumably. Flow is the main control to turn the radiator on and off. The return you set with an allen key. Am wondering what the return valves should be set at? Can adjusting them increase the temperature of the radiators? Is there anything I should know/ should /shouldn't do?

 

Thanks.

[BEngo]

The return valves are there to enable the system to be balanced- where the temperature drop is the same across every radiator.

 

In a boat it usually does not matter  if the rads are not perfectly balanced, unless one is not getting hot at all,  so most folks just leave them fully open.

 

How many radiators do you have, and do they all get hot, to roughly the same extent?

 

To do a balance you need to open all the valves fully and run  the heating.  Wait till the system is hot.  Measure the inlet temperatures at each radiator using a clip on thermometer, or better, an Infra Red thermometer. Dont forget the calorifier, if fitted.  You should have valves on that  to balance it in with the rads.

  The inlet temps should all be the same, within a few degrees of the Ebby set temperature.  If not there is a flow restriction somewhere, or a badly designed system.  You need to fix that first , if needed. 

Then measure the outlet temperatures. Again these should be the same, but probably won't be.  Adjust the outlet valves by closing the hottest one a little and waiting 5 minutes before checking the temperatures again.  Rinse and repeat till all the inlet temperatures are the same and all the outlet temperatures are the same.

Pour yourself a treat, fit the valve caps   and hide the Allen key so no-one  can bugger about with the valves !

N

 

 

 

[nicknorman]

… and as a general starting point, have the furthest away (from the Eber) radiator’s valve fully open, then progressively slightly restrict the flow to the radiators nearer the Eber, so that there is equal flow to all the radiators taking into account the friction in the pipes.

 

We have another valve that controls heat going into the calorifier, you may or may not have that heating loop into the calorifier. Generally it’s best to keep that valve closed unless you actually want to heat the water - well on ours, anyway, if it’s left open it can thermosyphon back through the heater over night etc, thus cooling the hot water.

 

[MtB]

13 hours ago, P1PPA said:

The return you set with an allen key.

 

This is to stop the users fiddling with them and upsetting the balance of the system!

 

Having said that, heating installers often CBA to balance a system they've just installed as it means an hour of fiddling with it. They commonly just leave all the balancing valves wide open. Equally commonly, they are too feek to understand properly what is required and how to do it (as explained by poster above). 

[blackrose]

If they are thermostatic radiator valves I would just take them all off. What you don't want is radiators shutting down when the rads get hot and TRVs close, which then sends hot water back to the eberspacher causing is to cycle down and eventually coke up.

 

My newly installed Webasto Thermotop C was cycling down too early until I took the TRVs off and chucked them in the bin. The heater now runs a lot better. On closer inspection the instructions actually stated not to have TRVs on the rads.

[jpcdriver]

Eberspacher do give installation advice that says TRVs can be used, especially with the newer models that can vary output, as long as one radiator (e.g. towel rail) and calorifier are always in circuit and balanced properly. Webasto advise against using TRVs.