Simon Brooke

Yes ,I think I might try that.

Simple step would be to insert ball valves either side of the Wilo? I could be more radical and remove the Wilo altogether?

Approximately 3.5 metre run of 28mm plastic.

Thanks John. I will contact Samsung tomorrow.

Wunda technical have advised that if the blending valve is fully open there should be no restriction.,Does this sound correct?

The Grundfos has a max power of 48 w. The Pico shows a power consumption of 4 to 40 w. Pump body arrow is correct.

It is a Grundfos UPS2 25-40/60. Search indicates 6m head and max flow of 3m3. The only indicators are green bars which show a max of 3. Flow gauges reading approx 1.5 and there are 10 loops averaging 90m using 16mm Wunda pipe. It is ages since I ran the heating using the Sun amp but I am pretty sure that the required flow rates of an average of 2.25 were achieved with the single grundfos pump. Again , thanks for everyone’s input.

Interesting. I will investigate further tomorrow.

Good question! The information plate is impossible to photo clearly. I would have to loosen the pump to see.

Many thanks for all the comments. The model is AE090JXYD EU. It does not have it’s own pump. The loops are pretty much fully open, in fact one completely undid to much merriment!. Pumps on max. Any thoughts on the idea that the two pumps may somehow be conflicting with each other?

Finally got a plumber to connect up my Samsung ashp. This is to take the place of a heat battery. The system is as simple as possible with no zoning. A second pump has been added (a Wilo Pico), in addition to the original Grundfos supplied with the u/f kit. I would have liked to have had the blending valve removed but this was too much for the plumber! The maximum flow rate per the Pico read out is 0.9m3 which I am assuming equals 15 lpm. The manual indicates that I need 17lpm so not fast enough and I get a low flow error code each time I try to run it. Research on the net seems to give me two options. The first is to install a new pump with a greater speed capacity and the second is to somehow run the two pumps in parallel which seems to increase the flow speed. A final option is to move the second pump from its current position of being on the return to the heat pump to being on the flow side. If it is not already clear I am not a plumber but should be capable of simple pump replacement etc. Any thoughts welcome.

My Ventaxia has a silent running mode which I have assumed means that the fans are running at minimum rates. The time period is adjustable via the touch screen.

After two years of living in our new self build we are generally very happy with our passiveish house. We have an underfloor system fitted but not really operational as the Sunamp is not man enough ( though does provide our hot water very well). We would like an ashp but only need input for a month or so and therefore reluctant to spend big money. I am now considering a second hand ashp and would really like it to be reversible so that we can cool as well as heat the slab. Getting information from dealers or manufacturers as to which model would be suitable is proving difficult. I do have access to a five year old Daikin EDHQ014 B6V3 but the online manual indicates that cooling is an option but not applicable to all models? Does anyone have a recommendation for a model / manufacturer which would easily switch from heating to cooling? Also is it sensible to think of a five year old model or should I stick to new? Any advice gratefully received.

Simplest and cheapest would be to just move it. The boiler should have a few years of life left in it. The only issue for me would be whether you are happy with water pressure for showers.

Shutting off the bedroom heating has made a big difference. Last year when we ran the underfloor heating as recommended we found that the 9kw Sunamp ran out of puff very quickly leading to cold water rather to often. As noted on other Buildhub posts the mvhr is not that efficient in redistributing heat so we have an approx. 2 degree difference in the room temps. The cooler bedrooms suit us , the only downside is that the bathrooms which are part of the bedroom loops (bungalow) are a bit chilly and definitely need the towel rail boost. I recognise that our approach is a compromise and does make proper use of the underfloor heating but the costs of an ashp ,both capital and servicing , coupled with the disruption to the finished build are putting us off that route.