Jamesessex

Ah yeah the model number is VWZMWT150. The DMH hot already comes on at 2am for 2 hours when the radiators and underfloor heating is off. The DHW and heating are never on at the same time. The UFH comes on at 5 am and the rads upstairs at 7 am. After 3 hours the UFH had still not brought the temperature downstairs from 19.5c to 21 degrees hitting only around 20.5. The rads upstairs do this in 90-120 mins. the maximum the flows go to is 5, they are on 3 at the moment. Is there is any risk attached to increasing them to 5? Not so worried about energy costs just needing the heat. most of the floors are laminate with the living room being a thin pile carpet. just spoken to Vaillant from the checks done over the phone they don’t think one of their engineers can help as the air source heat pump appears to be working fine. They suggested increasing the system max temp to 50 degrees c. Spoken to the house builder this morning and they said they would just refer to the installer who has already been twice and doesn’t seem to know what to do. Sounds like I need to find a specialist UFH engineer to come out and inspect it all and see. Maybe the installer has spotted the problem and doesn’t want to say in the hope I will just go away

Hi, no gas on the development just an air source heat pump in the garden. The house is 2 years old, I’ve recently moved in. There is the cylinder and then another vaillant unit which has a sticker on it which says SM 1 inhibitor. No more pumps from what I can see. Thank you

Thanks for your note. Here are a couple of photos of the hot water tank area upstairs

Thanks, it’s fed from a vaillant boiler which uses a valiant air source heat pump. On the system control for the boiler it is showing as the heat pump having a flow temperature of 42 degrees c. When touching the pipe it feels barely warm at all.

Thank you. I have chased the plumbers a few times but suspect they won’t call back. I’ve located the flow rates but cannot see the temperature gauge, would that be via the pump settings? Many thanks

Ah yeah the tank is heated again by the heat pump for an hour in the afternoon for the small amount of hot water needed in the evening. Most of the hot water is used in the morning only after the overnight heating

Hi, the heat pump comes on at 2am until 4am and then the immersion heater does 4am to 6am

Hi, apologies if this topics has been posted previously but would be very interested in views. I’m living in a new build house with underfloor heating and an air source heat pump both of which I’m new too and appreciate I need to get used to them. Downstairs is underfloor heating with radiators upstairs. The products are all Vaillant with Heatmiser thermostats in the rooms. There are so many different settings and features and I’m keen to keep things simple. The upstairs radiators work well and I’m happy. It’s the downstairs. I have the underfloor heating set for 22 degrees at 6am reverting to 21 at 9am back to 22 at 4pm changing to 20 at 9pm. All thermostats have a 1 degree variance setting. The house is very well insulated and so the temperature between 9pm and 6am drops by just 2 degrees to 20 (with outside temp of 2-4 degrees) and therefore the heat required is 2 degree increase with 3 hours power time between 6am and 9am. What I’m noticing though is the upstairs radiators make the increase in temperature within about 90 minutes of kicking in at 6am but the underfloor heating struggles. Typically the lounge will increase from 0.7 degrees in 3 hours (switches off at 9am before even reaching 22), the hallway increases 2 degrees in about 3 hours and the kitchen areas about 1.2 degrees in 3 hours. I’ve had an engineer visit twice. The first time he told me to put the underfloor heating on a temperature of 24 degrees and hold permanently for 2 days to heat the floors up. I did as he suggested and found that the kitchen made it on the second day but the floor heating was very patchy in the living room and hall. Only half the floor was warm. He came back a second time and adjusted the flow level from 1 litre per minute to 2 litres per minute. This has definitely resolved the patchy heat problem and improved the heating up times (it was something like 6-12 hours before for 2 degrees increase) I’ve contacted the firm again and they said in an email that I need to make sure the hot water isn’t heating at the same time as the general heating ideally a couple of hours after (it is already set up so both run at different times) and that 21 degrees is probably the most I can hope for. I was a little disappointed with their response and before I pay for another engineer to visit I thought I would share here for any advice. What I’m looking for is the downstairs to heat each morning from 20 degrees to 22 degrees in 3 hours or less. Is that possible with an ASHW and underfloor heating? I’m satisfied from testing the thermostats all work. The ASHW has a min temperature flow of 25 degrees and max of 45 degrees, the curve is set to 1.7. Thank you for any advice

Very grateful for any advice. it’s a new build property with a vaillant air source heat pump. the domestic hot water is set to a temperature of 60 degrees for which the air source heat pump manages around 45 degrees and then an immersion heater kicks in to get this to around 60. My question is how frequently should the immersion be used to obtain the 60. is this best daily or less frequent. 45 degrees is more than adequate for showers etc but appreciate the bacteria issue of not heating to 60. I’m wondering if it is acceptable to heat the water to 45 degrees 6 days a week and then have the immersion on for day 7. Many thanks