# My heat pump is too big, what should I do? **URL:** \ **Category:** Heatpump\ **Created:** [6 November 2023 16:27 UTC](https://community.openenergymonitor.org/t/my-heat-pump-is-too-big-what-should-i-do/24706 "2023-11-06T16:27:52Z")\ **Posts on this page:** 1\ **Showing post:** 203
**Author:** ![Stephen\_Crown](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/stephen_crown/32/26680_2.png) [@Stephen\_Crown](https://community.openenergymonitor.org/u/Stephen_Crown)\ **Post date:** [20 December 2023 17:08 UTC](https://community.openenergymonitor.org/t/my-heat-pump-is-too-big-what-should-i-do/24706/203 "2023-12-20T17:08:59Z")
> [@Rob-G](#): > > I have all the TRV’s in the bedrooms set to 20c(18c at night) otherwise they get too hot all the common rooms bathroom, kitchen, dinning room, living room are set 24c and all sit at 21c quite happily. > > The reason I set the TRV’s a couple of degrees above where I want the temp is the TRV’s seem to be optimised for GAS CH so start shutting off the valve as they approach the set temp but I have found this does not play well the lower flow from the heat pump. Indeed, to avoid starving the heat pump of water flow (which also drives up the flow temp if you hit minimum output) you really want to try and set the downstairs TRV’s to the maximum setting (or remove the head entirely) - similar to what you’ve done. Any differences in heat output/room temperature can be dialled in through balancing (assuming the radiators are generally able to meet the peak heat demand for the room) > [@Rob-G](#): > > So if my understanding of the MMI is correct then at 10c the set point for the flow is 33c. It looks that way - assuming you have a heat curve defined? I’ve found going lower than sat 32C or so doesn’t really work that well from an efficiency perspective on my system. YMMV. Switching to LWT mode and the 4C overshoot may result in some overheating, but you want to then reduce the weather curve (but not too far) - and it should allow balancing to be done if you can get to a steady state. If rooms are not getting to temperature, ensure the valves (not the TRV as that should already be at max) are fully open. Any rooms that get hot too quickly or overheat, start closing the valve little by little. Unfortunately, most valves only start restricting flow rate at a certain point, and then they are very agressive, so you can turn and turn with nothing happening, and then all of a sudden the flow stops…its at that point you’ve found the “authority”, and then its’ trial and error: room too cold, open slightly. room too hot, close slightly. There is a thread specifically on balancing here as well…: > [@Radiator Balancing - is there an idiots guide?](https://community.openenergymonitor.org/t/radiator-balancing-is-there-an-idiots-guide/24721): > > I’ve been reading the monster Daikin thread with common references to radiator balancing. I’m convinced some of my short cycling issues are due to poor balancing. Very much like Marko says, the house is getting warm but i’m seeing more cycling than I’d hope. Even though COP hits Vaillant specs!! My confirmed and recorded heat loss at -3C last winter is around 4kW, so my 5kW Arotherm is not oversized etc. I’ve messed about in the past and opened some up “a quarter of a turn”. Bu… --- _[View the full topic](https://community.openenergymonitor.org/t/my-heat-pump-is-too-big-what-should-i-do/24706)._