marshian

Gutted for you - good luck with removal and replacement - hope it goes perfectly

Yes

Good trick for pinch points for vented systems is to put a magnet against the copper pipework - if it sticks to the pipe then you've got a magnetite build up - how much you can't tell but you've definitely got an issue in that location

I had to do this a few years back when I air locked the boiler - it works quite well But if you aren't prepared with people at F&E tank and any bleed points it can get a bit damp

Well your water bill is gonna thank you even if the in laws and the fam don't

It's witchcraft - that's all you need to accept - once you accept that it's really easy to understand 😉 I set mine up to target a flow temp which resulted in my house being stable internally at 0 Deg C OAT (I started high and worked down - probably quicker to start low and work up but Mrs Alien was not keen on "freezing her ass off while I fecked around with the heating" (True statement) My slope target flow temp at 0 deg OAT ended up at 33 Deg C which in my case was 0.6 as a slope (with no level correction) Once you have the slope you can then fine tune the level All the level is doing is compensating for the fact that heat loss is proportional to temp differential - higher the difference between inside and outside the faster the heat loss example at -2.5 OAT and 21 deg inside the delta is 23.5 Deg C at 10 Deg OAT and 21 deg inside the delta is 11 Deg C So heat from inside moves slower to outside when the differential is lower so proportionally you need to put less heat in to cover for the escape because the escape is at a slower rate So at 10 deg OAT my target flow temp was 27 Deg C and the house over heated so I needed to drop the level to target 26 When I drop the to -3.0 on the level on a slope of 0.6 it changes the target temp at 0 Deg C OAT to 32 Deg (and I want 33) So I increase the slope to 0.7 and that gets me back to 33 Deg C at 0 deg C OAT Told you it's bloody witchcraft

1 - Good 2. What the heck is one of them - picture of the pump please or did you mean an auto bleed above the pump in the pipework somewhere? 3. Hmmm - we'll leave that one to one side for now

Sometimes it's easy to miss the obvious - I had a gate valve fall apart internally (cold feed to my loft tank - took me ages work out why the tank used to take bloody ages to fill up after a bath - only after a lot of trial an error and checks did I find it wasn't fully open) another reason why I bloody hate gate valves and why I replace them at the same time as a pump if they been a long time Good point well made If it's air locked there opening a drain under the boiler (if it has one might encourage the air to escape (or cracking the union on the ope of the boiler (more towels)

I'll get shot for suggesting this but.................... 1. You did open the isolation valves up after fitting the pump? 2. You did bleed the pump after fitting (centre screw loosen it to allow the air out - they don't pump air at all well 3. Are you sure the isolation valves actually opened I'll get me coat

Can you not glue the broken piece back on?

^ WHS even in the -6 we had in early Jan my flow temps didn't go above 38 Deg C and the house was comfortable All rads sized for 35 Deg C flow temp at -2.5 Deg C OAT and sized to meet the heat loss of each room at that temp

Bucket and towels Leave the spade for the beach

Yeah but they look a bit leaky!!! Perhaps that's just me!!!

I hear you but in my experience the pump valves have normally been in a heck of a lot longer than the current pump and are normally badgered Time before last when I replaced a pump the valves were badgered and I did it with the acceptance of some water leakage The next time I replace the pump I did pump and valves with a partial drain down - when that pump failed the valves held with the next pump replacement Caveat - I've been in this house since 1991 so it not like I've burnt thro pumps

I bought a DAB but since hearing what you can do with the head adjustment from @John Carroll if I ever have to replace it I'll go for Wilo Drop in replacement I think I'd do the job properly - drain system down and replace the valves at the same time as the pump but that's because I'd want to give the valves the best chance next time the pump needs replacing

As the scaffold boys drop the boards down you can take the worst off easily with one of these https://www.screwfix.com/p/magnusson-floor-scraper-8-/110PR?tc=JB4

I fitted a PIV unit centrally in the house (4 bed over two floors) as a result of humidity levels spiking after I insulated under my suspended ground floor (great idea from a heat loss perspective but it had clearly been a major contributor of uncontrolled air ingress) Within a few days the PIV unit had brought the house into a level of control initially on a higher flow setting but now it's on a timed schedule (midnight to 6.00 am and 8.30 am to 3.00 pm as this works for our occupancy routine. I did buy one with a heater but 400W consumption can rapidly increase electricity usage when it cuts in so I've got it turned off. I do have trickle vents in a few windows (not all because most predate the requirement) but a fair percentage of the air pushed into the house is ventilated out via bathrooms fan extracts even when the fans are off. (this is exactly what I need as dry air expels the warm wet air in bathrooms) Overall it works well for us

Current winter daily average HW heating is 4.5 kWh at £0.052 per kWh No solar, no battery and std fixed electricity rate at £0.26 per kWh - be a big increase in cost to heat direct via immersion only We only ever heat direct in summer during heating system improvements (have some more planned for 2026)

Good teacher 😉 I would have never thought to look for one on auction sites (figured they would be all unsuitable cyl's removed as upgraded from heat pump installs so no real advantage for me) Retail appears to be just over £1,000 Slightly cheaper than going with PHEX unit and pump but suffering the same heat losses from my existing cyl A lot cheaper than converting a direct cyl with a PHEX and pump. Manufacturer claims at a 58 deg flow temp coil output is 8 kWh so my 30 min HW re-charge should still be possible even with a little more capacity I think my HW coil size is probably tiny in comparison (would have been designed for high flow temps) best guess less than 0.5 m2

Right inspired by @JohnMo's bargain hunting I've been looking for a replacement HW tank Criteria/Requirements Unvented (but must have manufacturers approval to be installed in vented configuration) 150 Litres Max (Space restrictions and it meets the household needs from a daily consumption perspective) Immersion heater at the base (this is fairly std) 2m2 Coil surface area (I'd like 3 m2 but it seems tanks below 200 L are typically 2 m2 and only at 200L do they go up to 3m2 coil and I don't want a 200L plus tank) Eventually I found one brand new but ordered in error for what looked like a decent price Unvented 150L, 2 m2 coil surface area, immersion in the right place, but didn't want to make an offer until I had contacted the manufacturers to check if it could be installed in a vented set up (reasons are covered earlier in the thread) Made a cheeky offer and £450 it was mine just got go fetch it now

I'd put a PIV unit it and just run it over night - you could probably run it on the lowest speed (2 W consumption) and at that rate it's not going to cost much at all to heat the incoming air We run ours on setting 3 overnight (7W) so that's 30 Litres per sec in a 291 m3 House volume it gives us an ACH of 0.37 We have tried it on a lower speed but we get condensation on the inside of the windows in the main bedroom so we'd rather have a higher ACH and no condensation and a little more energy spend heating the cooler air that is being forced into the house

Hmm that's interesting - Thank you A double version of what I currently have 1600 x 472 has an claimed output of 1579 w I could easily increase the height to 1800 x 472 and that has a claimed output of 1750 w It seems neither will get me to target (closer but no cigar as they say)

I'm debating upgrading the two bathroom rads They are verticals - I purchased them in 2023 when I was still using the previous glow worm boiler that couldn't cope with a flow temp below 45 and I had to fit aftermarket diverters to make them work properly (picture below was from a thread on rubbish quality rads) Last winter I was transitioning from scheduled heating at higher temps to 24/7 with weather compensation so the bathroom temps were a lot warmer Now I've been running flow temps in the winter of low to mid 30's the bathrooms only reach 21 deg C - personally I find that OK but Mrs Alien feels that they need to be warmer (she does however like a long bath. They are rated at 0.89 kW at T50 - heat loss of the bathrooms is pretty much identical at 220 w What I'm trying to get my head round is how much larger a rad I need to get to a target of 23 Deg C with my current flow temps (I know I can get a double version of the on I have and Mrs Alien is happy with the asthetics.............. The current rads wouldn't go to waste as one could replace a towel rail rad in downstairs toilet and another in the utility room (both the towel rails used to be in the bathrooms but couldn't get the rooms to temp at 45 deg flow temps so were relocated to replace 1980's single panel single convectors rads rather than wasted) The utility room in particular has additional heat sources, tumble drier, Freezer, Fridge and washing machine so needs very little additional heat I might ask ChatGPT to see if it can work out what wattage I need to hit 23 seeing as that's the current trend for everything PS No the rooms wouldn't be continually heated to 23 - I'd manage the rooms temps with a setback when not bathing!!!

Avg energy consumption was 3.81 kWh Total Consumption was 38.1 kWh (38.1 divided by 10 hrs)

OAT overnight -4.4 Deg C highest temp in the day -0.2 Deg C but it wasn't there for long All internal room temps held nice and stable Boiler ran from Midnight to just before 10am with one burn (it finished that burn just before the HW cycle was scheduled probably due to OAT warming up or the modulation blips threw the flow temp over target. Avg energy usage for that period 3.81 kWh That's quite impressive considering the modulation hiccups it has on a regular basis Looking like my heat loss calcs are a little more than actual ~4.25 kWh @ -2.5 OAT From my Octopus account Gas usage over the 24 hr period Overall the whole day saw the boiler do 7 cycles (normal is 20 to 24) Bloody modulation blips annoy me still..............