TRV's on Radiators Problem

[uncleg]

Hi, I have a quick question which I am hoping someone can help me with so that I am armed with facts before I confront my builder and his plumber mate!

I have a Vaillant megalflow unistor with an eco tec plus boiler, all works well.

At first I could not get the water hot without having to put the central heating on, but was told that the temperature for the water is controlled via the cylinder so ignore the water temp gauge on the bolier and leave it at apporx 9 o'clock - is this right?

Second point the water and heating on/off is controlled via a control timer near the cylinder, I also have a room thermostat in the hall way (for the heating) and then there is the heating control temp knob on the bolier. Also I have TRV's on all the rads. I decided to test it at the weekend (first time) and the heating and boiler all work fine, but the rads only get hot when the TRV's are set to max 5. Any lower they get cold, so it looks like they have just an open and closed valve mechanism? Is this right? what is the point of the TRV then? what does the heating temp on the bolier do?

Please can someone assist so that I can ask the right questions. Apologies for the amny questions.

Many Thanks

 

[Baxi-Remeha]

trv will open and close depending on the temp of the room. im guessing when you tried them it was quite warm....

 

[seco services]

abit of a job testing a trv in this weather
at present my room stat is reading a temp of 27 degrees indoors.
so even if i was to put heating on the trv's won't open less i open them to a high setting.

 

[uncleg]

Thanks for your replies.

Makes sense, but is it right that when they do come on at the max setting (5) that when you turn them down to 4 they get cold??

Or is it as the valves are not opening until 5 (as it is warm) then any lower I am in effect turning them off?

Thanks

 

[D_Hailsham]

... is it right that when they do come on at the max setting (5) that when you turn them down to 4 they get cold??

Or is it as the valves are not opening until 5 (as it is warm) then any lower I am in effect turning them off?

The numbers on a TRV represent the room temperature you want to maintain. So 1 may mean a room temp of 10C, 2= 14C, 3=17C, 4=20C, 5=22C etc. If you room temperature is higher than the TRV setting, the TRV will stay closed and the radiator will be cold.

TRVs are not like switches, on/off, open/closed. They open and close gradually so the flow through the rad is just sufficient to maintain the required room temperature.

In your case the room temperature must be somewhere between that represented by 4 and 5. The temperatures should be in the TRV literature, or you can find it on the mfrs web-site.

 

[uncleg]

... is it right that when they do come on at the max setting (5) that when you turn them down to 4 they get cold??

Or is it as the valves are not opening until 5 (as it is warm) then any lower I am in effect turning them off?

The numbers on a TRV represent the room temperature you want to maintain. So 1 may mean a room temp of 10C, 2= 14C, 3=17C, 4=20C, 5=22C etc. If you room temperature is higher than the TRV setting, the TRV will stay closed and the radiator will be cold.

TRVs are not like switches, on/off, open/closed. They open and close gradually so the flow through the rad is just sufficient to maintain the required room temperature.

In your case the room temperature must be somewhere between that represented by 4 and 5. The temperatures should be in the TRV literature, or you can find it on the mfrs web-site.

Thank you very much, apolgies if my questions appear very basic, I just want to ensure that I have got a working system for which I apid for.

Thanks again