Hi Richard. I fitted one of these with a vaillant heat pump recently and I piped it up A to rads and B to cylinder, I wired it the opposite way around to what you suggested. It seems to work fine but is there any downside to doing one way or the other?
Hi Andrew! As per the manufactures instructions, the black wire is defined as the 'switch live' wire. Fitting it with port B to DHW and wiring it with the brown wire as the switched live wire will work, but in the interests of keeping things standardised, on your future installations consider keeping port A for DHW and black for the DHW switched live (the next man or woman that comes along will thank you!).
@@MWPHS Thanks. I’ll reverse it when I go back to do the service. Another thought I had about the way I’ve done it, it’ll mostly be in heating mode which in my case will be fighting the spring action of the body. I’m not sure if that’s of any consequence 🤷🏻♂️
@@andrewalderson1 when fitting it with the A port to space heating, the cartridge would need to be actuated down to close off DHW which could potentially reduce the life of the cartridge over time. The way I would be fitting them is how I have described in the video.
Hi Richard. I fitted one of these with a vaillant heat pump recently and I piped it up A to rads and B to cylinder, I wired it the opposite way around to what you suggested. It seems to work fine but is there any downside to doing one way or the other?
Hi Andrew! As per the manufactures instructions, the black wire is defined as the 'switch live' wire. Fitting it with port B to DHW and wiring it with the brown wire as the switched live wire will work, but in the interests of keeping things standardised, on your future installations consider keeping port A for DHW and black for the DHW switched live (the next man or woman that comes along will thank you!).
@@MWPHS Thanks. I’ll reverse it when I go back to do the service. Another thought I had about the way I’ve done it, it’ll mostly be in heating mode which in my case will be fighting the spring action of the body. I’m not sure if that’s of any consequence 🤷🏻♂️
@@andrewalderson1 when fitting it with the A port to space heating, the cartridge would need to be actuated down to close off DHW which could potentially reduce the life of the cartridge over time. The way I would be fitting them is how I have described in the video.