Me too, unless there's a serious feck up in the piping!
-
Looking for a smarter way to manage your heating this winter? We’ve been testing the new Aqara Radiator Thermostat W600 to see how quiet, accurate and easy it is to use around the home. Click here read our review.
New two-port valve - water hammer on opening
- Thread starter dylan_t42
- Start date
Me too, unless there's a serious feck up in the piping!
Probably allready suggested but maybe run with the 2 port actuator removed and the valve left manually opened for a few days.
Also, the Spirovent is installed between the pump discharge and the MPV, maybe better to have it installed before the pump inlet.
Yes, that’s the cream one to assist the Megaflo. The original on the heating side was red (which makes sense) got replaced with the gray one (less so).
It is, as per IMG_1488, there’s big 22mm t-off from the cold feed to the Megaflo after the pressure control unit. Glad that aligns with expectations.
I don’t think that has been, but makes sense & we’ll test for a while. My expectation is that with the NC valve held open we won’t have the issue.
I don’t think there’s enough space above the flow pipe from the boiler to do that. It’s too close to the ceiling.
Last edited:
Couple/three other things which we’ve considered:
* Is there an Integrated Flow Check valve in the Wilo Pico pump that might allow a pressure difference
- No evidence the PICO pump has such a device; plus hard to see how it would have this effect
* Might the pump benefit from a run of the de-aerator function?
- Pressed the button & waited 10 mins while it ran, will advise IDC
* Could the old Califei(?) air-vent at the top right of IMG_1490 be holding some air?
- We were told to keep the black plastic bleed screw locked down to avoid air being sucked into the system
PS: And thanks for the continued input. Very much appreciated by both of of us.
* Is there an Integrated Flow Check valve in the Wilo Pico pump that might allow a pressure difference
- No evidence the PICO pump has such a device; plus hard to see how it would have this effect
* Might the pump benefit from a run of the de-aerator function?
- Pressed the button & waited 10 mins while it ran, will advise IDC
* Could the old Califei(?) air-vent at the top right of IMG_1490 be holding some air?
- We were told to keep the black plastic bleed screw locked down to avoid air being sucked into the system
PS: And thanks for the continued input. Very much appreciated by both of of us.
No, no check valve, I have one of those pumps myself.
I've also installed a few of these pumps in relation's and I didn't use this air venting function in any of them, no harm in using it, it just varies the pump speed up and down for this 10 minute period.
What you might try, even though not the recommended mode, is PP (proportional pressure), note the pump power in watts, W, in whatever CC mode you are now running on, CC2?, then turn the setting knob anticlockwise into the houses, stop turning it occasionally, it will then flash the selected PP head and then display the power in watts, keep adjusting it until the power is exactly the same as it was in CC mode, see does it make any difference.
Just open the Caleffi AAV blanking cap now and then to check for any air.
Last edited:
FIXED !
A brief update now that we've had a working fix for a couple/three months.
We got in another local company who went through the issue & all the items documented here, agreed that the issue was a build-up of pressure between the three-port valve & the safety two-port for the HW tank, and came up with a wiring solution that has eliminated the problem.
In short, the two-port HW valve was opening when the HW cylinder thermostat called for heat, releasing pressure built-up during CH operation. The solution was to instead wire it through the over-heat safety cut-out so that instead of closing when the tank came up to temperature it will now only close when the tank detects an overheat condition.
So the HW two-port is now held open during normal operation of just the CH, preventing pressure build-up, but will still close if the HW cylinder becomes too hot during the DHW mode.
Thanks again for all the input & hope this helps someone in future.
A brief update now that we've had a working fix for a couple/three months.
We got in another local company who went through the issue & all the items documented here, agreed that the issue was a build-up of pressure between the three-port valve & the safety two-port for the HW tank, and came up with a wiring solution that has eliminated the problem.
In short, the two-port HW valve was opening when the HW cylinder thermostat called for heat, releasing pressure built-up during CH operation. The solution was to instead wire it through the over-heat safety cut-out so that instead of closing when the tank came up to temperature it will now only close when the tank detects an overheat condition.
So the HW two-port is now held open during normal operation of just the CH, preventing pressure build-up, but will still close if the HW cylinder becomes too hot during the DHW mode.
Thanks again for all the input & hope this helps someone in future.
Absolutely - In a Y plan with an unvented, the 2 port is there as a safety device not a zone valve, if it's wired as a zone valve then it's not doing what it should and why it's fitted.
It should always be wired through the HL stat as that is the primary fail safe cutoff for the unvented and the 2 port is the safety device that isolates the unvented from the heat source, in that failure condition, it's why a Y plan (3 port) must have a 2 port fitted to the primary.
It should always be wired through the HL stat as that is the primary fail safe cutoff for the unvented and the 2 port is the safety device that isolates the unvented from the heat source, in that failure condition, it's why a Y plan (3 port) must have a 2 port fitted to the primary.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local