marshian

So are advantages of split units using refrigerant things like no glycol/antifreeze valves, no defrosts and a higher flow temp is possible than A2W Heat pumps? The COP from memory was high 3’s in middle of winter and high 4’s to low 5’s in shoulder seasons House is a fair size (so will cost to heat) but to me the energy bills over winter are eye watering it was built 6 years ago to regs UFH throughout with additional big towel rails in all the bathrooms what concerned me from an efficiency perspective was the buffer, number of pumps in the system and thermostats in every room

I wasn’t questioning the modulation 😉 The boiler will have a min flow temp that it can work at - that temp may well be higher than a UFH system can cope with my old Glow Worm boiler stated min flow temp was 39 deg C - it wouldn’t run at that temp - lowest practical operating temp was 45 current boiler min flow temp is 20 deg - lowest practical operating temp is 25 deg should be documented in the installation manual

I think it must be

I don't think @mikeysoft's WB LPG Boiler is capable of the low flow temps for UFH - and probably not able to do DHWP either

Data is always good - I'm seeing an improvement in both internal humidity levels as well as loft humidity levels Changes have been driven by Improvements to loft insulation (from 75mm to 300 mm) and ventilation (eaves trays and gable end vents) (Loft temps are rising, humidity levels are falling) Changing the speed of the PIV unit for the shoulder and summer months (Increased Air changes and air supplied from the loft is drier) I was tempted to move my internal temp and humidity monitor as it's in a relatively cold room compared to the rest of the house but because it's always been there I'm reluctant to have a change in data. Add to that the insulation levels above the room have been improved I'm hoping I can heat 24/7 without setbacks

I'm guessing it's high temp split with refrigerant I only noticed the pipe size because the insulation is also quite small and is in a poor state in places - guess that might be impacting efficiency?

Went to my friends house this weekend - fairly large bungalow with a ASHP set up Looked at the heat pump and was really surprised to see the primary pipes are tiny (like microbore size) I was expecting 28mm pipework from the ASHP to inside

I am right in thinking that ring circuits is very much a UK thing and stems from "economy" post war - less wire used and lower grade of cabling required? In Europe they are radial??

Just to add Setting 2 has been my winter setting but Setting 4 has become my go to setting for spring summer and autumn Reason is adding insulation to my loft has resulted in an increase in loft temps - the PIV cuts out if loft temps get over 27 deg C So it's running half the time it would during winter so I've increased the flow rate and it seems to work nicely - especially at night when the loft temp rapidly falls and it's helping to cool the bedrooms during the night. The silver fan of doom hasn't been deployed yet this year (Mrs Alien doesn't like it hot in a bedroom in the summer so despite the fact she's a light sleeper the fan gets deployed and as it's a constant noise she copes with it - I can't stand the noise it makes although I can sleep thro a hurricane I can't get to sleep in one so dislike the fan being deployed) In spring / autumn during the day it does a reasonable job in transferring warm loft air to a cooler house

Christ!!! That's quite a number. /joke - But then again if I'd applied to build a dungeon under my house I'd have probably got a few more oblections Having said that with the water table as it is it would be a below ground swimming pool 90% of the year and a little drip would be the last of my concerns 😉 How many of the neighbours still don't talk to you?

I had three objections to a two storey extension to the house and a single storey extension to the attached garage (all in one application) All were from an immediate neighbour. 1. Over development of the land (from neighbour with less garden than I would have post extension) which made me chuckle. House extension was replacing the footprint of an aluminium single glazed conservatory and garage extension was replacing a wooden shed. 2. Concerned about the possibility of running a business from the garage (I like cars I have a few and I do all my own maintenance / restoration - not got time to do work on other cars) 3. Proposed new window for en-suite would overlook neighbours bathroom window (their window was frosted glass - proposed new window was specified as frosted glass) Planning was granted

Home made induction heater was what I called it Anyway apologies for the OT back to ring mains and fused spurs

I’d better state the case for defence (of the lazy) 1. it’s the shortest immersion I could find (seriously stubby) 2. it will heat approx 30 litres of a 115 litre tank before tripping out on thermal overload (temp of the water thermal overload - not melting the plug thermal overload) 3. it is absolutely a get out of jail solution for major gas boiler breakdown/failure 4. I’m well aware it’s probably well past the ragged edge of acceptable just an aside I once needed to do a bit of welding on a car - rather than turn the car round so the welder could be plugged into it’s normal 16 amp socket - I plugged the welder into an extension lead (un coiled just what was needed to reach the welder) that ended well…….. Next time I used the extension lead it uncoiled to the same point - the rest had welded itself together / scrap basically

you’ve just reminded me I need to wire in my 3kW immersion heater to a fused spur connection off the ring main (rather than the current 3 pin plug it’s currently wired into) before I turn off the boiler, drain the system for a couple of days to do a few circuit/rad valve changes prior to the heating season. yes I know it shouldn’t be on a 3 pin but in 33 years it’s only been used twice (very much a energency use only)

flipping the question round why would you want to switch the flow off to the UFH and rads if it’s heating season?? Well set up weather compensated flow temps should mean that the heat source is only replacing the heat lost not more and not less…..

reminds me of the Urban Plumbers Skit on Viessmann Boilers and why the company makes life so difficult for installers Skip to 11 mins and enjoy

Pretty much what @JamesPa said I'd certainly try WC first with as much of the system in play as possible before adding lots of thermostats and micro zoning I've currently got Wiser "Smart" TRV's on every Rad (13 in total) The only ones that actually have some room influence are on the north facing side of my house with 3 external walls on the rooms and they are used to set back temps during the periods where we aren't using those rooms and overnight for same reason primarily because of the high heat loss. All the others are set to an elevated target temp and act as temp limiters rather than temp controllers (for solar gain on south side or an unexpected and sudden temp change outside) I'm going to try to re-coup some of the cost by selling the smart TRV's and replace them with decorators caps as really they are just expensive battery powered room temp sensors and I have stand alone units already in most rooms

I mostly DIY because - with the exception of plastering and brickwork - when I've paid a tradesman to do work it's not been to a standard I regard as acceptable - that doesn't mean it's shoddy or terrible it's more that they want to get the job done in the minimum time and it shows. Your maths works and makes sense but I enjoy the satisfaction of knowing 1. I did it myself and 2. If I need to maintain/alter/replace something I know how it was put together (I tend to think of the access requirements at the fabrication stage and build it in)

Excellent progress - getting vehicles stuck on site is fun................ One of my treasured memories is getting a cement lorry stuck in my back garden after delivering 15T of concrete and it buried to it's differential casings due to driver not understanding that spinning the wheels from the start was unlikely to do anything other than dig a really big rut. Seeing it pulled out by another one - happy days.............

Fun comparisons Weekdays Roughly Translated to Sleep - Wake up Get Up - Work - Get Home - Have tea - drink tea - bed Weekends Roughly Translated to Sleep - 1 person wake up - get up and do stuff - 2nd person get up - stick on laundry 3 loads - tea Oven - watch movie - bed Winter is heavier on laundry due to TD/dehumidifer drying usage

Or too high a pump speed for the system volume and lockshields screwed down to slow the flow (aka "balancing not balancing") One of my pet hates is system noise - I won't repeat the post I wrote around pump getting blocked up with magnetite resulting on the need to run the pump as twice the previous speed and generating a lot more system noise as a result But this was the pump impeller and once cleaned up I was able to revert to the previous min speed and had a perfectly quiet system again......

I guess it depends on what electrical kit is running mine averages around 300W background load.

so it the HW heating on demand via temp sensor (ie as soon as sensor sees 5 deg lower than target temp it tops up) or timed to once a day? with a 250 litre tank and lowish usage you could run cooler temp and use more of the tank if heated once a day - if you have visitors either heat to a higher temp (change the bi-metalic sensor to higher temp or increase frequency of re-heat at same temp) our tank is typically down to ~30 deg overnight and reheated in ~40 mins in the morning (using ~3 kWh of gas to do so) winter when cold water is coming in at a lower temp (10 deg) it’s down to 20 deg overnight and reheated to ~55 deg in 20 mins in the morning (house losses are increased in winter) (using ~5 kWh of gas to do so) It’s what works best for us…..

Easier viewing than the HG Website

If it's a loop that supplies all the hot taps and as a result no delays in HW at the tap then it's returning to the tank and is not what I would term avoiding stagnation because legionaires isn't just about stagnation it's about controlling the temp of the water store to avoid optimum growth temps. If you are using all the water in the tank every day then risk is much reduced We only have a 115 Litre tank - we heat to between 48 and 50 deg C and heat just once a day (except on bath night) We pretty much use all of the water every day with 2 showers morning and evening plus a little washing up Is your HW loop 24/7 or on a timer to minimise tank losses - if it's on for long periods of time it will be dragging down the tank temp and as a result you need to run the tank hotter to compensate and it won't be helping the plant room temps