MrPotts

WB don’t support Opentherm either. I have seen that resister mode before but it only works on the newer boilers. At the time I had the boiler installed I didn’t know about boiler capabilities and thought I was getting a top of the range boiler (that’s what the installer told me), what I actually have is a basic boiler with virtually no control other than setting flow temp.

I can buy a diverter kit and convert from a 2 pipe to a 4 pipe system but the expense makes it unviable. My boiler is a basic WB Greenstar from 2015 so it’s not the best unfortunately and just missed the cutoff point where some extra control was added. Even the ebus connection is disabled. i think I will experiment with setting the DHW to have its own programmed schedule separate from the CH and see if there are any efficiency gains to be made.

For energy efficiency is it a good setup to have PDHW when my system boiler can only run at a single flow temperature. The system at the moment is an Splan. Thanks

52kw heat loss is massive for a residential building, my house is a third of the size but 7 times less heat loss. Does the building have any historical importance?

Smart TRV’s such as Tado, Hive etc are just basic on/off controls with a bit of fancy marketing around their “smart” features. Having said that I have a hybrid Wiser system where I use a combination of smart TRV’s and manual TRV’s.

What is the purpose of the 2 port motorised valve? It looks like it isn’t doing anything.

Again this is just what I have read but increased thermal comfort and reduced noise level do not justify the increased cost.

From what I have read the additional cost doesn’t justify triple glazing over double glazing.

I wonder if the MCS registered companies are just adding the BUS grant onto their quotes for free money! Worth getting a quote from a company not MCS registered. This is what happens when a monopoly is created. It would be great if an MCS installer would comment on why their prices are so high but I wont hold my breath.

I find it very frustrating that the consumer is once again being taken advantage of. The £7.5K BUS grant is taxpayers money that could be used elsewhere rather than lining company pockets. If we were quoted fair prices an ASHP (after the grant) would be free!

Are installers now quoting and then adding on the BUS grant as free money in their pocket? £15k seems like a lot of money for a heat pump, HW cylinder and labour.

I have a system boiler with the pump controlled by the boiler pcb with a 3 minute pump overrun. This is normal operation. My thoughts are that either the motorised valve or the ABV is the problem.

I have a gas boiler and s plan configuration. More often than not whenever the CH motorised valve closes i hear water hammer, just a single thud, its been happening for quite a while. This only happens with the CH motorised valve, the DHW motorised valve works as expected with no water hammer when it closes. I have a Honeywell auto bypass valve which is on the default setting of 2. Could it be an issue with the motorised valve?

That is where I changed them. When I then selected which temperature for morning, afternoon etc that is when I got the #ref errors. I will have another go tomorrow.

Thank you for this detailed information, it is extremely useful and certainly gives me confidence in the Heatpunk results. I have already selected the correct depth of loft insulation within Heatpunk. Looks like most of my radiators will need replacing if i decide to go ahead. The Heatpunk recommended heat pump is an Vaillant aroTHERM plus 7. The heat pump load is....... The Outside Design Temperature for postcode AL5 is -2.3°C At the Outside Design Temperature and a Flow Temperature of 45 °C the output power of the heat pump is 8563 W. The heat loss from the building at the Outside Design Temperature is expected to be 7689 W. The total area of the building is 157.98 m2, giving an average heat loss of 49 W/m2. Thanks for all your help. The Outside Design Temperature for postcode AL5 1HG is -2.3°C At the Outside Design Temperature and a Flow Temperature of 45 °C the output power of the heat pump is 8563 W. The heat loss from the building at the Outside Design Temperature is expected to be 7689 W. The total area of the building is 157.98 m2, giving an average heat loss of 49 W/m2.

I have had a look at the epreadsheet but it doesn't work for me. If I change the default temperatures I get the #ref error.

Hi James All that I have done is increase the loft insulation from 100mm to 300mm. The house temperature usually drops to about 17c in winter, about 19c in summer.

@JamesPa We have a 4bed detached house built in 1996. The annual gas consumption figure came from our smart meter. A few questions is the house warm enough? Yes 20-21c. Whats your heating pattern? Heating on 7-10am and 4-10pm is it a gas boiler, how old. 9 year old 24kw gas boiler. What does your EPC say your consumption is. Not got an EPC, we have lived here for 25years. In the spreadsheet calculation, what are the assumptions about the fabric that you cant verify, particularly air changes per hour? I just entered room sizes, radiator sizes and building fabric details, all other assumptions were left at defaults. Where in the country are you/whats the local design temperature. North Hertfordshire, design temp was -2.3c

Sorry, I meant 12,500kWh

I use just under 12.5kWh of gas in a year. That also includes hot water and cooking on a gas hob.

If I use the rule of thumb on Michael de Podesta's blog then I need a ASHP of 4.28kW, I have also gone through the process of working out a heat pump size on Heatpunk and that states 7.69kW. Which is right, I have no idea!

The inflated MCS prices are costing us the taxpayers! The government needs to investigate why ASHP installations via an MCS installer are so expensive.

Was it installed off centre to allow the shower door to open?

What is it with this forum adding words I didn’t type !!

My wife experience is different, in my house once the rooms reached their set temperature then more often than not they would request heat individually. This was probably due to the differing heat loss per room.