Boiler/water pressure issues

Albermarle

FreeBear said:

Replacing the vented tank with an unvented one might be an option - This would improve flow & pressure to all hot taps and shower without having to replace the boiler or lots of pipework. Would cost a bit more than just a pump though.

Just for giggles, I'd be tempted to see what Octopus would quote for a heat pump. It would include a new DHW tank plus a few radiators - Have heard of installations under £1K.

Presume that would solve the problem, as both hot and cold would then be at the same mains pressure.

I wonder what sort of cost to fit a new unvented cylinder, especially as you need a heating engineer with the requisite qualifications ( G3?) £1000 ?

KaratePigeon

Wow, thank you so much for explaining it. Was it the valve you wanted a photo of?  Yes the controls in the airing cupboard aren't the most convenient, especially when I've got my bedding and towels stashed in there 😅 I guess I could just leave the heating on in there and use the dial to turn it on and off. 

Sounds like I need a new or fixed valve then, a pump on top of the boiler and a digital thermostat would be nice but that can wait until next winter. Then I should get reasonable pressure with mixer shower so the kids will prefer that one and I'll put up with the mediocre electric one but at least it'll be all mine 😁 then in a few years rip it all out and get either a combi or a heatpump. 

KaratePigeon

I just did the online octopus quote for a heat pump and it said £3.9k, I wonder who qualifies for the really good offers 🤔

FreeBear

KaratePigeon said: a digital thermostat would be nice but that can wait until next winter.

A programmable thermostat that allows you to set different temperatures throughout the day could save you up to 15% on gas (saving is likely to be around 5% though). If you are a high user, payback could be less than a year.

I had been running at 16-17°C overnight, and ~19°C during the day. Dropping to 17°C for most of the evenings during the week (I work late shifts), and then 19°C for a couple of hours when I get home. Currently experimenting with a 16°C baseline 24/7, with heating kicking in at 08:00 until it gets to 19°C, and repeat again at 12:00 and 20:30 (weekends have extra slots at 15:00 & 18:00). Temperature only drops ~0.5°C over 3 hours and it looks like I'm using slightly less gas. Can only do this with a smart(er) programmable thermostat.

KaratePigeon

FreeBear said:

KaratePigeon said: a digital thermostat would be nice but that can wait until next winter.

A programmable thermostat that allows you to set different temperatures throughout the day could save you up to 15% on gas (saving is likely to be around 5% though). If you are a high user, payback could be less than a year.

I had been running at 16-17°C overnight, and ~19°C during the day. Dropping to 17°C for most of the evenings during the week (I work late shifts), and then 19°C for a couple of hours when I get home. Currently experimenting with a 16°C baseline 24/7, with heating kicking in at 08:00 until it gets to 19°C, and repeat again at 12:00 and 20:30 (weekends have extra slots at 15:00 & 18:00). Temperature only drops ~0.5°C over 3 hours and it looks like I'm using slightly less gas. Can only do this with a smart(er) programmable thermostat.

I don't think I'm a high user, definitely don't have the heating on at night (do most people?) I mostly work from home but even then I try and avoid putting the heating on until the kids get back from school. (I've got a heated throw when I'm at my desk, I love it 😊) 

FreeBear

KaratePigeon said:

FreeBear said:

KaratePigeon said: a digital thermostat would be nice but that can wait until next winter.

A programmable thermostat that allows you to set different temperatures throughout the day could save you up to 15% on gas (saving is likely to be around 5% though). If you are a high user, payback could be less than a year.

I had been running at 16-17°C overnight, and ~19°C during the day. Dropping to 17°C for most of the evenings during the week (I work late shifts), and then 19°C for a couple of hours when I get home. Currently experimenting with a 16°C baseline 24/7, with heating kicking in at 08:00 until it gets to 19°C, and repeat again at 12:00 and 20:30 (weekends have extra slots at 15:00 & 18:00). Temperature only drops ~0.5°C over 3 hours and it looks like I'm using slightly less gas. Can only do this with a smart(er) programmable thermostat.

I don't think I'm a high user, definitely don't have the heating on at night (do most people?)

Although my heating may be set to 16-17°C, I've not seen the boiler fire up at all over night. During the daytime, I get quite a bit of solar gain when the sun shines, so again, the boiler might not fire up. And if I light the fire, the boiler may not run at all in the evening.

ThisIsWeird

Weird Iflo make, but it comes up as a Drayton model, MA1. If it's a faulty 'actuator' - the top plastic box bit - you can pick up a new one from around £35 (eBay), and it's easy to fit (even very DIYable, if you are competent).
See the wee lever/indicator on the side? It'll move to 'W' (water) when the valve has been operated to send the flow to the hot cylinder, to 'H' (heating) when sending to the radiators, and 'M' for both.
Ok, the simplest way I can think of to check whether it's a stuck actuator is to use that LP112 programmer to turn the CH off the next time it stays on when it shouldn't.
Familiarise yourself with the 'select' button under the cover, on the RH - Heating - side. This will scroll the setting through 'off', 'once', 'timed', and 'on', yes? Ok, wait until the next time the CH doesn't go off when the room stat tells it to, and press the 'select' button until it goes to 'off'. The indicator light should go off.
When that light goes off, it cuts the power to the room stat, so even if the room stat is stuck 'switched on', it won't actually be getting power, so it cannot send that 'on' signal to the boiler. 
So, if turning the programmer to 'off' doesn't shut off the boiler, we cannot blame the room stat. However, we can still suspect the motorised valve, as that item receives its own separate power supply, so can send an 'on' signal to the boiler if it's faulty and stuck, regardless of the programmer.
So, please try that; the next time the boiler keeps running when it shouldn't, turn off the programmer using the Heating 'select' button. 
If the boiler keeps running, then try a karate chop on the motorised valve - strike it with something solid but non-damaging, such as a shoe! Give it a few blows, and listen for any whirring sound. Also check the side indicator - where it is before you start hitting it, and see if it moves

ThisIsWeird

D'oh! I completely missed one of the most important details in your photos - the top of the hot cylinder:

This shows the hot water as it exits from the hot cylinder. It is unfit for your setup as you have a pump added to the hot-water draw, and is almost certainly at the root of your 'air' issue.

If you trace that pipe - I can't quite see it in your photos - I suspect it comes to a 'tee', with one pipe heading upwards to your loft, and the other heading downwards to, possibly through, the floor? Ok, the 'upwards' pipe is the 'vent', and goes up to that CWS tank in the loft, arches over it, and points down into it. That pipe 'vents' away any air in the hot cylinder, and also acts as a safety discharge should your cylinder boil, say if your immersion is stuck 'on'. The lower pipe simply carries your hot water to all your taps.

When you open a hot tap, the weight of water in the CWS pushes cold water into the bottom of the cylinder, and forces the hot water out the top - the hot water is 'pushed' out by the higher-up Cold Water Storage tank.

That's all good. But then you add a pump to the hot water draw... This now sucks the hot water out of the cylinder, and the CWS supply to the bottom can struggle to meet demand. If that happens, the pump still keeps on sucking, and it can sometimes draw in air via that vent pipe if it finds that easier than taking hot water from the cylinder.

So, you need a Surrey Flange fitted, and yours doesn't have one.

I'm not going to say that this will sort your problem, but will just point out that what you currently have at the top of that cylinder is not 'proper' in a couple of ways, and you clearly do have an air issue. So, I think it will.

A surrey flange should be fitted, with the hot water take-off coming away sideways as it is now, but the vent pipe should be taken to the top of that Surrey flange, and not tee'd off as it is now.

What the Surrey flange does is to take the hot water from a few inches down inside your cylinder - it has a short pipe that goes down in there - and that then avoids any air bubbles at the very top, but also makes it far less likely that the pump can draw the water out of the vent pipe - resulting in air being drawn in - which I suspect has led to your pump failure issue.

Surrey flanges are around £20 upwards, and can be fitted in under an hour if now't goes wrong.

Could you, please - take some photos to show that pipe and where it goes? And, any chance of taking the bath panel off and showing us yer pump? If it screeched only because it was drawing in air, but is otherwise undamaged, then there's every chance it can be reused once the Surrey has been added. 

As for your bath shower mixer, I wonder if one of these wee booster pumps on the DHW side - say under the bath - would do to nearly match the 'gravity' hot with the 'mains' cold?

https://www.bes.co.uk/in-line-automatic-shower-power-booster-sp2b-22904/

ThisIsWeird

The alternative solution - one I generally like as I hate pumps - is to add a dedicated cold supply from the CWS to your bath mixer.

But, I'd only do this if I was confident that the CWS would supply a nice enough flow to your shower - ie it is positioned high enough up in the loft to provide enough 'head' above the shower handset position.

Could you try, please - fit the handset in its holder at its highest point, and then turn on only the hot tap. Take a pic of the resulting spray. What's it like?

Assuming it's 'ok' (tho' probably not 'brilliant'), then imagine it being, say, half as good again - ie when the cold water is added.

IF it's 'ok' either on its own (ie just the hot running) or if it'd be ok if another halfish-amount is added (roughly - I'm assuming ~60oC hot + enough cold to bring it down to ~40oC), then you should provide a decent shower using only 'gravity'. Ie, with both hot and cold being supplied from that CWS. That means, no pumps :-)

I have to point out, tho', that your lovely tap - although they claim it's also suitable for 'low pressure' systems - requires a min of 0.5bar pressure, and that equates to 5 metres of 'head'. Ie, your CWS would need to be 5 metres higher up than your mixer. I'm going to hazard, 'not a chance'!

So, sadly, with that mixer, I fear the 'gravity' solution is not going to work. But please do try the hot-water-only test to confirm.

KaratePigeon

Sorry for the late reply. I was hoping the plumber who came last week would have got back to me with a quote for some options but nothing yet 🙁 I have been bombarded with calls from octopus to see if I want to buy a heat pump though 🤣

That pipe that comes from the top of the cylinder just goes horizontally into a T, the upwards pipe just disappears into the ceiling, and downwards through the floor. 

The shower with just the hot turned on makes a gentle spray. 

The pump under the bath (as I bought it last year) is this one,  as a plumber recommended it 🙄 https://www.screwfix.com/p/salamander-pumps-ct55-xtra-regenerative-single-shower-pump-1-5bar/13775?gclsrc=aw.ds&gad_source=1&gclid=Cj0KCQiA_NC9BhCkARIsABSnSTZJQcgdqpLVjKnL7eekZ3v4ehOoNZz7SGWGGmBiFPhauRJR6-2-vEUaAhgoEALw_wcB it's just connected to the hot water pipe