What Valencia valve parts to buy?

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  • MrBoy
    Automated Home Guru
    • May 2017
    • 165

    What Valencia valve parts to buy?

    Fitting my house for EvoHome I have got some adapters for the old Drayton TRVs in about half the rooms - these seem to work well so far. The other radiators either have manual valves or old TRVs which no adaptors exist for (that I can see) so I plan to fit new valve bodies. It seems Valencia are the best bet but even here something simple is likely to trip me up.



    Ignoring the top 3, are the 2nd row sets containing the bodies to go in BOTH ends of the radiator? One end has the pin for the TRV, the other is a manual on/off (the lockshield)?
    Then the bottom row are just the TRV-ready body, one comes with a regular TRV, so I save about £2 per radiator. Or for that matter, I can buy the valve with a regular tRV for only £2 more.

    If my radiators are working OK is there any particular point to replace the lockshield manual bit? Thinking I might as well get the TRV-one and I can surely sell them for more than £2 each when I fit the HR92?!
  • DBMandrake
    Automated Home Legend
    • Sep 2014
    • 2361

    #2
    I plan to replace all my Peggler Bulldog valves for Valencia's - when I do I'll just get the TRV end and leave the existing lockshields alone - they're only a couple of years old and work fine. Unlike the TRV end which is constantly adjusting and needs to move smoothly and precisely, the lockshields only have to stay put at one setting, which even cheap ones will...

    If my lockshields were a bit older or more tatty then I might have replaced them as well.

    Comment

    • HenGus
      Automated Home Legend
      • May 2014
      • 1001

      #3
      My installer replaced all my TRV bodies with Valencia bodies when my boiler was replaced last year. I was hoping that there might be fewer clunks when the HR92s first opened. Sadly, that hasn’t been the case. The original lock valves were not replaced.

      Comment

      • paulockenden
        Automated Home Legend
        • Apr 2015
        • 1719

        #4
        If your lockshields are old I'd be tempted to replace them at the same time, while your system is fully drained down. Only adds a couple of minutes to each rad, and might safe you work in the future.

        Comment

        • darrendobson
          Automated Home Jr Member
          • Nov 2015
          • 14

          #5
          Agree with Paul change them why its drained down especially if current ones are old

          Comment

          • TomJ
            Automated Home Lurker
            • Jan 2018
            • 7

            #6
            You could also consider getting valves that regulate flow regardless of the water pressure (within limits of course). This makes for even more efficient heating as all rads always perform the same, regardless of the amount of TRVs closed. I've just installed 20 Heimeier Eclipse 1/2" valves without a hitch. The HR92s fit them without an adaptor.

            In The Netherlands they are just over 20 euro each. Please also see https://www.imi-hydronic.com/sites/E...s/default.aspx for better explanation.

            Comment

            • MrBoy
              Automated Home Guru
              • May 2017
              • 165

              #7
              Originally posted by TomJ View Post
              You could also consider getting valves that regulate flow regardless of the water pressure (within limits of course). This makes for even more efficient heating as all rads always perform the same, regardless of the amount of TRVs closed. I've just installed 20 Heimeier Eclipse 1/2" valves without a hitch. The HR92s fit them without an adaptor.

              In The Netherlands they are just over 20 euro each. Please also see https://www.imi-hydronic.com/sites/E...s/default.aspx for better explanation.
              thanks, I'd not seen them.

              Comment

              • DBMandrake
                Automated Home Legend
                • Sep 2014
                • 2361

                #8
                Originally posted by TomJ View Post
                You could also consider getting valves that regulate flow regardless of the water pressure (within limits of course). This makes for even more efficient heating as all rads always perform the same, regardless of the amount of TRVs closed. I've just installed 20 Heimeier Eclipse 1/2" valves without a hitch. The HR92s fit them without an adaptor.

                In The Netherlands they are just over 20 euro each. Please also see https://www.imi-hydronic.com/sites/E...s/default.aspx for better explanation.
                Looks good on paper however I'm not sure how much difference that would make in real life in an Evohome system and whether it is applicable.

                The reason being, it's not just differential pressure that will vary when the demand of other zones change, the boiler flow temperature will change dramatically as well due to the way every individual Evohome can call for heat from the boiler - and that's a much larger factor controlling how much a given zone is influenced by what other zones are doing...(like a previously stable zone at equilibrium overshooting because other zones just came on full blast)

                If anything, some variation to differential pressure of a conventional valve will "help" reduce interference between zones - when other zones close down the heat demand will drop and the flow temperature will drop but the pressure will increase through the remaining radiator possibly partially counteracting the natural tendency for its temperature to drop.

                Conversely when other zones come on and demand a lot of heat the flow temperature will increase due to the higher boiler duty cycle but the differential pressure will drop and reduce the flow through this radiator a little. Regulating the flow through each valve irrespective of differential pressure would only make that worse.

                So I don't see a point to it with an Evohome (assuming you have an ABV to iron out the biggest changes in differential pressure) and counterintuitively it may actually cause more interaction between zones instead of less.

                Comment

                • DBMandrake
                  Automated Home Legend
                  • Sep 2014
                  • 2361

                  #9
                  Originally posted by HenGus View Post
                  My installer replaced all my TRV bodies with Valencia bodies when my boiler was replaced last year. I was hoping that there might be fewer clunks when the HR92s first opened. Sadly, that hasn’t been the case. The original lock valves were not replaced.
                  Clunks ? From where ?

                  No clunks in my system when HR92's open or close...

                  Comment

                  • Dan_Robinson
                    Automated Home Ninja
                    • Jun 2012
                    • 347

                    #10
                    Would suggest pump set too high with valve bodies on the return.
                    Kind Regards - Dan Robinson (Jennings Heating Ltd)

                    Comment

                    • HenGus
                      Automated Home Legend
                      • May 2014
                      • 1001

                      #11
                      Originally posted by Dan_Robinson View Post
                      Would suggest pump set too high with valve bodies on the return.
                      Thanks. I will chat to my installer. The something was happening with my old boiler and separate pump. The clunks, as far as I can tell, are the the HR92 bodies hitting the adapter as there is a certain amount of twist/play.

                      Comment

                      • TomJ
                        Automated Home Lurker
                        • Jan 2018
                        • 7

                        #12
                        Originally posted by DBMandrake View Post
                        Looks good on paper however I'm not sure how much difference that would make in real life in an Evohome system and whether it is applicable.

                        The reason being, it's not just differential pressure that will vary when the demand of other zones change, the boiler flow temperature will change dramatically as well due to the way every individual Evohome can call for heat from the boiler - and that's a much larger factor controlling how much a given zone is influenced by what other zones are doing...(like a previously stable zone at equilibrium overshooting because other zones just came on full blast)

                        If anything, some variation to differential pressure of a conventional valve will "help" reduce interference between zones - when other zones close down the heat demand will drop and the flow temperature will drop but the pressure will increase through the remaining radiator possibly partially counteracting the natural tendency for its temperature to drop.

                        Conversely when other zones come on and demand a lot of heat the flow temperature will increase due to the higher boiler duty cycle but the differential pressure will drop and reduce the flow through this radiator a little. Regulating the flow through each valve irrespective of differential pressure would only make that worse.

                        So I don't see a point to it with an Evohome (assuming you have an ABV to iron out the biggest changes in differential pressure) and counterintuitively it may actually cause more interaction between zones instead of less.
                        I'm not an expert at all but asked a CH engineer to help me on this one:

                        The problem I was facing was that if only a few smaller zones were asking for a lot of heat, the boiler produced 75 deg water, but the rads only managed to cool it down by 5ish degrees (because of the high flow speed). Causing the boiler return to still be very hot, and allowing it nowhere near condensing operation, and thus being pretty inefficient. I've now limited flow in the rads to achieve a deltaT (output - input) of around 20 deg when facing 70deg input water temp. My previous thermostat used to be more conservative, firing up the boiler at lower temps, so I think for my situation, with evohome there are higher benefits from the reduced flow speed through the rads than before. In morning operations, I regularly see deltaT over 30 degrees, whereas before the new valves, it was closer to 15.

                        The pressure overflow helps reduce the pressure and thus flow in the system, but returning the hot water to the boiler immediately does not allow the boiler to run in condensing mode.

                        The house does take a bit longer to warm up though, but feels less toasty around the rads in the morning.

                        I'm not sure what ABV stands for, sorry. Googling gives me alcohol related responses only. I do appreciate a drink every once in a while if that was your question

                        Comment

                        • Dan_Robinson
                          Automated Home Ninja
                          • Jun 2012
                          • 347

                          #13
                          Automatic bypass
                          Kind Regards - Dan Robinson (Jennings Heating Ltd)

                          Comment

                          • paulockenden
                            Automated Home Legend
                            • Apr 2015
                            • 1719

                            #14
                            Originally posted by Dan_Robinson View Post
                            Automatic bypass
                            valve. ;-)

                            Comment

                            • TomJ
                              Automated Home Lurker
                              • Jan 2018
                              • 7

                              #15
                              Originally posted by Dan_Robinson View Post
                              Automatic bypass
                              Originally posted by paulockenden View Post
                              valve. ;-)
                              Ah thanks, nowhere near the dutch "overloop" that I liberally translated as overflow ...so please think ABV when you read overflow above.

                              Comment

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