Not putting the heating on – how’s it going…?

Wiki suggests 32W per tealight.
Google suggests £5 for 100 is the going rate.

So 3.2KW of energy for £5.

Doesn’t seem that cheap even before you burn your house down…

So having had a few rads refusing to heat up downstairs we got a guy in to do a powerflush today.

While the pump was running got all of the rads nice and hot, flushed out loads of crap and refilled with clean water expecting it to sort the problem.

Back on to the normal pump and the same rads are still not getting off cold.

The powerflush didn’t bypass any valves so we can rule that out.

Shouldn’t be any muck left in the system either.

Pipes either side of the pump are very hot and the pump is whirring away like a good ‘un and was cleaned out during the flush and found to be in good working order.

Rads were working fine last Spring and didnt’t notice anything over summer, but why would you. Heat in downstairs rads didn’t stop overnight, they got gradually worse over a month or so when we started using heating more in Autumn.

All upstairs rads getting nice and hot and if we lock them all down it still isn’t getting the downstairs ones any warmer.

Short of taking all of the floors up ( a little difficult with a wheelchair user in the house) does anyone have any thoughts on what else it could be.

Wheres the boiler?
Is it system or combi ( no hot water tank)?

Airlock somewhere when it was refilled.

Boiler downstairs in Kitchen, pump in airing cupboard upstairs, boiler is heat only. HW tank in loft.

HW all fine, rads upstairs all fine.

System all bled after refill and it’s doing exactly the same thing as it was doing before.

If we have to lift the floors we have to find accessible accommodation for our daughter and her care team so any insights would be greatly appreciated.

Wiki suggests 32W per tealight.

I read 80.

@smokey_jo I think your pipes are fine if the powerflush worked. Have you tried increasing the pump flow/pressure? I would speak to a plumber if I were you and ask what your options are.

Pump is on max and according to the plumber able to pump a higher flow than a standard household pump. He said the powerflush was pushing around 4-5 times the flow though so would be more easily able to overcome anything partially blocking pipework.

It’s looking like a floors up job

we have had similar in this cold spell, unfortunately the last rad on the loop is the living room one which is the one we’d like to get hot in preference, and it will eventually. But the others are calling for heat to get the TRV’s up to temp first so the hot water keeps going through them and by the time it gets to the living room it’s not hot enough to make a significant difference.

So I have to turn the bedroom ones down through the day to overcome that, and then reverse them and save the living room one in the morning. Except not now we’re all off work and college and want the living room warm all day, not just evening.

Which leads neatly to the blog my ex-colleague writes, I linked previously about his (mainly successful) attempt to effectively go off grid using heat pumps, solar and battery storage but his blog yesterday was all about whether keeping the house warm overnight is economical vs letting it cool and then heating it more to get back to temp.

Setback? Should you lower heating overnight?

Ok, that helps somewhat.
So you have a system boiler in the kitchen, and a traditional, indirect hot water tank, heated by the boiler, upstairs in an airing cupboard.
This is strange though ax its the reverse of what you would expect, hot rads downstairs and colder upstairs.
This is the limit of my knowledge of S and Y heating layouts but hopefully Bear will be able to come up with an answer.

I think the pipework from the boiler heads straight to the upstairs airing cupboard which would explain hot rads upstairs. I think the downstairs rads are after the upstairs ones on the circuit.

If I lock all of the upstairs ones off it still doesn’t the downstairs ones off cold though

Ok, by the power of googlefu i am now au fait with S and Y dhw systems.
I think your diverting valve might be issue here.
Although the pump is over specified for the task there is not enough flow or, and pressure to pump a decent rate round the system, but the power flush did.
So the hot ch fluid from the boiler is not making its way round the house sufficiently fast enough to heat the last, lower rads downstairs.

Habe you tried turnimg all the upstairs off at the locksheilds, not the trvs, amd, if you have one, shut off the hot water tamk inlet valve.

Then open fully the locksheilds and trvs downstairs

Be a fun 40 mins in your house this evening

Habe you tried turnimg all the upstairs off at the locksheilds, not the trvs, amd, if you have one, shut off the hot water tamk inlet valve.

Yup we tried that and nothing – not a sausage

It wasn’t as fun as you make out it might have been though

I think the pipework from the boiler heads straight to the upstairs airing cupboard which would explain hot rads upstairs. I think the downstairs rads are after the upstairs ones on the circuit.

This is the case in our house, the downstairs rads get less warm even if the system is balanced due to a longer unlagged pipe run. But they still do get warm.

But the others are calling for heat to get the TRV’s up to temp first so the hot water keeps going through them and by the time it gets to the living room it’s not hot enough to make a significant difference.

The rads aren’t in series.

Pump is knackered then.
If you manually shut off everything upstairs then no hot rads downstairs at all.
Did you check the return pipework temperature at the time?

Has it worked in the past?

What does the pump sound like? Bubbles or smooth hum?

Have you checked the bubble traps are working?

Was working fine in Autumn.

Pump has been inspected today and is fine.

Pump is smooth hum.

What does a bubble trap look like and how do I check it?

Return pipes are hot.

I have one lukewarm rad downstairs now after 3 hours of everything upstairs being locked off.

Trail_rat. Oh dear.
That’s a shame
I actually used to work in consumer protection in the 70’s. We would investigate such claims.

I asked a mate who recently retired about DFS constant sale (trading standards legislation on sale goods and claimed reductions specifies a set period during which the goods must have been sold at “full price”.) He said “yes, but legislation like that just doesn’t get administered any more. Budgets. A culture of deregulation.
So the buggers (all of em) can nowadays claim whatever they like.

Automatic bypass valve faulty is my guess.

Where would I find this auto bypass valve and how could I test whether it’s faulty?

Daughter had something very similar, three way valve had broken up inside preventing rotation of the valve seat. New valve fixed it .

Bypass valves are in newer boilers.
On an older set up you left 1 rad with open valves, usually the bathroom towel rail. So in the event every trv had closed down the pump is not pumping against shut valves leading to high pressure and overheating.
They are usually located in the lower parts of tge boiler and bridge the inlet and outlet pipework.
With an adjustable set point so you keep spme pressure in the system.
https://www.toolstation.com/22mm-automatic-bypass-valve/p36612

Bypass valves are in newer boilers.

Older systems can have external ones, we have one. I tested it by screwing it in and out all the way, I could hear when it started closing or opening.

If you don’t have at least 10% of the load on rads without a bypass then you need one; I do but I still have one anyway.

Thanks guys, I’ll pass that on to the HEng and see if it motivates some thought and action 🙂

Still thinking 3 way diverting valve is doing something weird.
Maybe jamming without fully moving through its range of motion
Tired motor or debris on the seats at a guess

HEng says he didn’t see a bypass valve on the system. It could be under the floorboards so will have to start pulling upstairs boards next.

If I can get away without pulling downstairs floor I’ll count it as a win

There might not be one – it’s unlikely to have been fitted in an inaccessible location, that would require deliberate bloodymindedness on the part of the installer.

It could be the 3 way valve. If you turn off the hot water, run a bath, then turn the heating on do you get hot water back?

Im leaning towards diverter valve sending flow round the cylinder permanently , or not fully switching between the 2 systems
Im flummoxed , but I just sell all the gubbins at work

I think you need to find the 22mm return pipe downstairs , are you on microbore? or PEx plastic barrier piped CH? or Trad copper with 22mm flow and returns then 15mm feeds to each rad off the loop?

If the downstairs 22mm pipes are too hot to hold on to there is no reason why the rads are still cold. Unless its something like an airlock or TRV fails to closed

So some overnight progress!

All upstairs Rads closed off and lockshields off got the first downstairs rad on the circuit hot.

Locked down that one and it got the next one hot.

By this time it was getting late so locked that one down and went to bed.

This morning the remaining 3 rads were all working, the final 2 not as hot as the 3rd last but still OK for room they are in.

As I’ve left for work I’ve opened the lockshields on the other downstairs rads and opened the other valves 1/2 turn off closed to see what happens.

All pipes to rads are 15mm copper, no idea what’s under the floor but it could well be 15 again. Upstairs is 22mm in the airing cupboard as that was a new install around 10 years ago due to moving a bathroom.

Interesting. My last rad doesn’t get as hot as the others due to being on the end of a long run, so that might not be avoidable.

Molgrips. Isn’t that a matter of “balancing”. Added a rad in a place we sold a while back and it was very much at the end of the run, basement of a 3 story house. It wasn’t heating at all, so the heating guy came back and tightened all the other lockshield valves a little, more on the rads nearer the boiler (called it “balancing”) – and that worked. In that case the lock shields throughout had been replaced and left fully open. Hence the lack of balance, as much of the heat was being lost through the earlier rads.

Trail_Rat. All. Update on my insulation efforts. It wasn’t possible to use the foam tubing on many of the pipes en route to the upstairs because they were only 10mm apart and from the wall. (Who designs clips fir heating pipes that are so tight to the wall!) . Those pipes leading upstairs were heating that utility room they passed through far too much. Wasteful.
So I pretty much had to use the silver coated. bubblewrap tape (I did consider spray foam but far too risky – a leak would have been a right mess). I overlapped the tape so it was predominantly a double layer. Tight around the pipes as per the instructions. .

The room definitely feels much much less heated now. Phew.
Now I’m thinking about heat loss to the well ventilated underfloor voids downstairs. I’ll have to swerve that though as it would be far too much disruption to lift all those boards.

So I pretty much had to use the silver coated. bubblewrap tape. I overlapped so it was predominantly a double layer.

You could have done felt then bubblewrap.

Molgrips. Isn’t that a matter of “balancing”

Yes, but that only works to a point and there are other inter-related factors at play in my system which is bargain basement. If you restrict flow on some rads they don’t end up as hot so that room doesn’t get as warm and may not get warm enough before the hallway does and turns the thermostat off. If you throttle the hallway down so it warms up more slowly then the boiler’s flow temp might get too hot and start short cycling. I currently have most of the rads throttled right down except the kitchen which is fully open, and that rad still is 10C cooler than the boiler flow temp which isn’t hot enough to heat the large and cold room. I could turn up the flow rate to the next setting (pump only has three discrete settings) but then the water is going through all the rads too fast and not cooling down enough so the return temps are higher resulting in lower efficiency. I could help this with larger rads in some of the rooms and a faster flow rate. But those rads would have TRVs so when they’re closed there’d still be the same issue.

This is all because this boiler won’t throttle down enough, and the pump only has three fixed settings. A new better boiler could give lower heat output when needed which would fix the short cycling problem, and an internal pump that can vary its own speed for optimum flow regardless of what rads are calling for heat.

But lagging the long run to the kitchen rad would help as I could keep the lower flow and still have the rad hot enough to warm the room. Of course, all the pipes should have been lagged, but hey ho.

Just done our monthly readings for Octopus, averaged 56h kW of gas per day over the last month, just over £7 a day to heat the rather leaky Victorian terrace. And that’s with our rather miserly heating schedule.

Similar usage to last January, which I don’t think was that cold, so we probably have reduced our usage a bit..

Energy by Ben Freeman[/url], on Flickr

Anyone done a proper test with reflective insulation behind the radiators?

I did one years ago, seemed to help slightly but I have now lost the rest of the roll, I think I threw it out.

Anyone done a proper test with reflective insulation behind the radiators?

I stuck some behind all the ones against solid walls many years ago as it was so cheap, didn’t really matter if it worked or not…

So I’ve knocked up a bit of an app that hopefully gives me an idea of how much oil I’m burning.

A Raspberry Pi stuck inside the cover of my massive (old) boiler listens once a minute for it running via a £4 USB mini microphone.
When the sound level is above a certain level (i.e. the boiler is running) if fires off a webhook message to IFTTT which adds a row to a google spreadsheet – it fires another message when the sound drops below a certain level (i.e. the boiler has shut down).
This gives me the burn duration from which I get the oil used (a 1.35kg nozzle uses 1.65L of kero per hour).

On my phone I have an app that gets data from the spreadsheet, filters it and makes it look better – it also gives me a total volume used and the associated cost.

There will be some error as the pi might have run the script just before the boiler fires up, but it would hopefully get it on the following run 60 seconds later. Missing 1 minute of burn time is equivalent to 0.0275L of kero…. so I’m not too bothered, plus the pi could miss the boiler shutting off by 1 minute so it kinda evens out a bit!

It will be interesting to see how well it runs.

We’ve just had a similar issue – my tale may give you some ideas…

Getting to the first cold weather in our new house showed our Central Heating (oil) was not really working as expected.

I’d already replaced the motor on the mid-position valve when we moved in as the heating was coming on with the hot water, but didn’t bother changing the valve.
The Boiler thermostat was set at max and running constantly, but the radiators were not anything like as hot as the boiler outlet.

Worked out that two of three rads downstairs were not flowing. They were getting warm but the return was cold.

First I found all of the lockshields wide open including the hottest rads, no chance of being balanced!
Closed all of the rads down and even with the pump on high and all rads closed and backed off 1/4 of a turn couldn’t get very good flow.

Assuming the rads/pipework must be blocked/airlocked, tried purging with a hosepipe on the bleed port – good flow both directions – no improvement.

Noticed that the feed to the Hot Water Coil was warm and decided that the diverter valve must have been passing to the Hot Water cylinder – so drained the system and swapped the valve entirely – still no change. Bugger.

Starting from absolute cold allowed me to realise that the downstairs Rad circuit was getting a hot return very quickly even with all rads still being cold on their returns. So somewhere I have a short circuit – but where…

Looking through previous estate agent photos on Zoopla, I spotted a radiator in the kitchen that has not been reinstated during renovation before we bought. The kitchen floor is Karndean on plywood, across half of the ground floor. Bugger.

Managed to find a bit of the circuit above ground boxed in behind the downstairs toilet, also found a 10mm flow and return heading off towards the position of the previously removed radiator. Bonus!

Started the boiler and as the heat started circulating, the 10mm pipes stayed cold – that’s not it then. Bugger.

Ended up following the pipes under the floor – including lifting carpets and cutting new traps (although thankfully not under the karndean) to check for heat in the return line.
Eventually I narrowed it down to the flow and return branch to the Living room.

Ahhhh, I bet there is an old back boiler in the open fireplace that is still connected…

Dismantled the sofa and lifted the carpet in the living room, no sign of any pipes heading to the fireplace, just the single radiator – but hang on… Some wazzock has connected together the flow and return at the far end of the radiator.
Effectively there is a 15mm shunt across the bottom of the radiator – that would explain it!

Bear in mind I’m looking through a 12″ single board width trap against the wall, a fix is tricky. Thankfully I managed to get my hand in with the pipeslice and then fit two push fit blanks – yes I have a dead leg, yes they are pushfit, but needs must!

Test fired the boiler again and found the problem had now shifted to the dining room. Same fix and try again…

SUCCESS!!!
Where success is measured as turning the boiler on and not getting a hot return for at least five minutes!
Turning the boiler stat down to a guestimated 60C, means a burner duty cycle of around 50% which should make a nice saving on oil usage. The rads are now actually heating the house!

Now all I need to do is get all the air out of the system and balance the radiators, then properly set up the boiler temp and flow rates.

Unfortunately we’ve used about 700L of oil for very little benefit before realising we had an issue…

Gas meter reader chap turned up yesterday, and just got gas bill emailed through for past 16 days – 1070kWh used! Seems a huge amount to me, and immediately had me questioning if something’s wrong, but then we’ve been used to a well insulated flat for years before, and this is our first winter in a 3 bed semi (2 of us wfh, Wiser set up, certainly not extravagant with the heating!).

Makes me wonder what the usage would have been like without the Wiser kit. At least it’s got milder of late.

This guy says you shouldn’t lag your indoor pipes as can reduce boiler efficiency. Any thoughts?

. Any thoughts?

Yep.  What he says is only really valid if you are trying to heat all of the inside of your house to the same temp.  If you try to not heat spaces you aren’t using, e.g. the basement with the boiler in it, storage rooms etc then insulating the pipes within those spaces or feeding them will be a good idea.  The thermostat on your radiator only controls the water going through the radiator not the water going through the pipes feeding the radiator (assuming the radiator isn’t at the end of a loop of course).  So insulating those pipes will save heat from the pipes heating up spaces you don’t want heated up

If you are  heating your whole house to the same temp he is of course correct