Webasto Top Water Temperature

[stevecarter]

The Webasto heater has been installed in my boat for a year and drives three radiators.

 

Ever since installation the radiators have got very hot - far too hot to touch. How can I reduce the temperature of the water?

 

Many thanks.

 

Stephen

[blackrose]

More radiators?

 

Out of interest why do you need to touch the radiators?

 

Hot radiators shouldn't really be an issue, most people complain about the opposite problem. However, if your central heating system isn't large enough to dissipate the heat produced and the water goes back to the Webasto hot then that can cause problems because the unit will cycle down and not burn as efficiently and gradually it will get coked up.

 

Is it a Webasto Thermotop C 5kW?  Three radiators doesn't sound like a lot unless they are big double panel rads.

Edited March 28 by blackrose

[stevecarter]

Thanks blackrose. No room for any more radiators and no second coil in the calorifier.

[blackrose]

If they're single panel rads you could change them for double panel rads of the same size.

[stevecarter]

blackrose, thanks you for your continued input.

 

The unit is a Thermotop Evo 5 kW heater with a variable heat output between 5kW and 2.5Kw.

 

The radiators in total are rated at 4.8kW.

 

I don't need to touch the rads it is just that they are so hot I can feel the heat a couple of feet away and I touched one to realise they are really hot.

 

The temp of the radiators at the feed is about 75 degC and at the return is about 55 degC

 

How can I adjust the heater so it only produces 2.5kW?

 

Stephen

Blackrose, missed your comment about the rads. They are two panel radiators.

[PeterF]

Have a read of the workshop manual which can be found at the link below. per the extract attached. 80degC is the target operation temperature at which the heater reduces the firing. As far as I know this is not user resettable. It might be with diagnostic kit.I

https://www.webastomarine.co.uk/products/thermo-top-evo-5kw-narrowboat-kit

[stevecarter]

PeterF,

 

That's really useful - thanks.

 

I had not seen this workshop manual before, having had only the installation manual and user manual.

 

So I reckon I need to reduce the waterflow so the water gets hotter and that will cause the heater to go into eco mode rather than being on full chat all the time. Does that make sense?

 

 

[PeterF]

As long as you do not reduce the flow too much and overheat the burner. However, it will still run at 80degC.