TRV valves

[TR1950]

Good morning
I am a newbie here and have a question about the fitting of TRV valves.
I have just had some plumbing work done on a downstairs cloakroom, which involved moving and fitting a new radiator in a new position.
The new rad is labeled inlet and outlet on the connections and also has a blocker inside. I have just noticed the plumber who did the work has installed the new pipework with the lnput and TRV to the outlet, and return to the input side of the rad. Everything seems to work correctly and the rad heats up OK and the TRV appears to control the rad temperature correctly.
My obvious question is, is it OK to leave as it is? or will it cause a problem further down the line. If so should I get the plumber back to sort it out?
I would add that the TRV manufacturer specifies it is unidirectional but also states the TRV should be fitted to the rad input side.
Any advice gratefully received.
Many thanks in advance.

 

[Johntheo5]

If a column rad then you may be lucky as some of these will not work properly, if at all, unless positioned correctly, the blocker is generally located close to the the inlet to force the hot water upwards and it will then heat up like a normal rad. I have all my TRVs installed on the returns as I think that it is measuring a more representative room temperature as the cooler rad temperature here will not influence the measured temperature as much.

 

[Madrab]

Doesn't matter what side the TRV is placed as long as the valves are bi driectional. What does matter is that the flow is fitted to the side marked inlet and the return is attached to side marked outlet. If they aren't the radiator wont heat up properly.

If yours does heat up correctly and when you turn the CH on the side marked inlet heats up first then it's all fine.

 

[ianmcd]

As @Madrab correctly says the TRV is irrelevent as long as the flow is in the correct port and it is a baffle or diffuser, it is not a blocker

 

[TR1950]

Thanks for the advice everyone I will speak to my plumber today see what he says. Ianmcd I called it a blocker because that's what the rad manufacturer calls it in their documentation.

 

[Johntheo5]

If its like this then he may be able to change it to the other end.

 

[Madrab]

rad manufacturer calls it

That'll probably be down to the incredibly poor chineses translation.

Turn on the CH, does the side marked inlet get hot first? Even then, if it all heats up properly then there's nothing to worry about.

 

[ianmcd]

Have to add to this post, I am seeing more and more of these "Designer radiators" every day, thay are absolute crap, I seen one leaking through pinholing after 3 months, have never and will never install one for anyone, total rubbish, had a customer who was in tears because she bought one for over £300 from Victoria plumb and the hanging brackets had not been Tapped, they told her to silicone it on, but hey they look good if you are female so who cares that they dont actually heat anything

 

[ianmcd]

Ianmcd I called it a blocker because that's what the rad manufacturer calls it in their documentation.

so what exactly does it block? I dont give a monkeys what the chinese for diffuser is, if it blocked then the radiator wouldnt work ?????

 

[Johntheo5]

It blocks the (hot) water from going straight along the bottom of the rad and out the other end without properly heating (or not at all) the rad, the main problem is that these column rads are very tall and the hot water which rises almost immediately in a "normal" rad cools down before it reaches the top so the hot water runs along the bottom of the rad,. (or something like that). Next time you get a chance shut off one valve on a normal rad and allow the boiler to reach full temperature then reopen the valve, the hot water will rise up almost immediately in the first 6ins or so at the inlet end, then run along the top and fall down fairly uniformly to heat the whole rad, uncanny really. The blocker ensures that the hot water has to go to the top of the rad in the first 6 ins or so and then behave similar to the normal rad. Some rads are piped with the inlet on the top and the outlet on the bottom opposite end (TBOE)=Top, bottom, opposite ends, but not as pretty looking as the normal BOE (bottom, opposite ends) plumbed rads

 

[Madrab]

Hot water won't just run along the bottom of a clean rad, it just can't. Physics and convection dictates that it will always rise, regardless of whether it has a baffle or not. A baffle will direct water specifically so the radiator heats up in a certain way but they can sometimes cause more problems that it solves. Had one where the baffle was loose, rad just didn't ever work correctly.

Just installed a new 1950x550mm 8 column rad, no internal baffle, all it needs was to be balanced correctly slowing down the water exiting the rad, heats up without any issue.

Do have to agree though, they only look good, they are absolutely rubbish at space heating. Customers think that if they match the output then they heat the room the same and they are so wrong. They are primarily radiant heaters, they have very poor air convection qualities. I always advise against them.

 

[ianmcd]

It blocks the (hot) water from going straight along the bottom of the rad and out the other end without properly heating (or not at all) the rad, the main problem is that these column rads are very tall and the hot water which rises almost immediately in a "normal" rad cools down before it reaches the top so the hot water runs along the bottom of the rad,. (or something like that). Next time you get a chance shut off one valve on a normal rad and allow the boiler to reach full temperature then reopen the valve, the hot water will rise up almost immediately in the first 6ins or so at the inlet end, then run along the top and fall down fairly uniformly to heat the whole rad, uncanny really. The blocker ensures that the hot water has to go to the top of the rad in the first 6 ins or so and then behave similar to the normal rad. Some rads are piped with the inlet on the top and the outlet on the bottom opposite end (TBOE)=Top, bottom, opposite ends, but not as pretty looking as the normal BOE (bottom, opposite ends) plumbed rads

wrong do more googling, it doesnt block anything, it diffuseses how the water is distributated through the radiator, if it BLOCKED it the radiator couldnt work, would be the same as closing either of the flow or return valves

 

[Johntheo5]

We live and learn.
I have only seen two, (relations, that I installed), looking into the rad they appeared to be solid plugs/stoppers, (if I had looked closer maybe they are not solid) it seemed to me that the water after entering a short portion of the rad will then move upwards. Can't see how they will act like a isolating valve(s).

 

[ericmark]

My mother house had the TRV on return with some radiators, what I found was the setting of the lock shield valve was critical when TRV is on the return, it is all down to speed at which the TRV can adjust, every Saturday at 12 noon my TRV heads exercise, they fully open then fully close then return to setting, and this takes around 3.5 minutes, if the radiator can fully heat up in 3.5 minutes then it will over shoot the temperature set at.

So with the TRV at supply end the radiator heats up the TRV faster than at return end, so the lock shield setting is not as critical, however I was able to set it with valve on the return end, just took a little more care.

I am told we should use a differential thermometer but I can't find mine, so I used the computer display

. If when heating required target less than current close the lock shield a little and vie versa. However it took some time, and has to be done in winter, so can see why plumbers use the special thermometer.

 

[Madrab]

I guess it just comes down to the actual definitions of the words and how they are used -

To block (phrasal verb (verb)) - where a material is used to stop the passage of light/fluid/gas or other material.
A Baffle (noun) - A usually static device that regulates/directs the flow of a fluid, light or other material.