New boiler time :(

[gman]

No, not like their putting a magnet on the water feed pipe saying it reduces limescale.

I have seen it mentioned in different places, and quite honestly, I think for the heating it is a waste of time as it is a sealed system except if you drain down or bleed.

For DHW systems it is a H&S requirement for schools and similar, so I assume that is for a good reason, and you have no option but to comply and show records of testing anyway.
(You then had to put a notice by the taps warning of "Hot Water" which made me laugh, as what else do you expect from the hot tap. Don't know if that is still a requirement though. 60C hurts, but will not cause scalding or permanent damage)

Just did a quick search and the first mention came up here https://www.bbc.co.uk/news/business-67197871

Not that the BBC is any more reliable than BG's sales talk.

I'll crank it up to the max and give the HW a flush. Might be beneficial for the drains as well. Speaking of which, a drainage guy we had out recommended Fairy Liquid once in a while to help keep the drains clear - he was specific that it must be the original green stuff. Apparently there's a chemical in it that is not in their newer lines. I guess it makes sense as it's supposed to dissolve grease. Sorry, going off topic now.

 

[gman]

Sitting at 42 with the heating not even on

 

[Sangoma]

Sitting at 42 with the heating not even on

View attachment 405191

What was that the temperature of?

Bit of update.

Some of the ideas that they use are attempts at one size fits all, and often don't help.

I have opened all my lockshield valves completely, set the CH water temp to 45C which keeps my return temperature in the condensing range all the time.
The only drawback is that it takes longer to get the house up to temperature in the mornings.

The new thermostat also causes it to take longer, but it does completely eliminate overshoot, and it turns on occasionally to prevent the temperature falling to the temperature at which it would normally start heating again.
The result is the temperature stays constant, avoiding the 1-2C cyclic rise and fall that makes you think it is getting cold

Keeping the return temperature within the fully condensing range is saving 7-10% gas, and the "intelligent" thermostat is saving about the same, plus the heating is on the 3 hours longer each day.

The radiators don't get hot, can easily hold them at their hottest, and they rarely get completely cold.

The only way I could get further improvement would be external wall insulation. Others round here paid 6-8000 for it.
I won't live long enough to get much of that back in gas savings

Overall though, much more comfortable, with some savings.

 

[gman]

What was that the temperature of?

Bit of update.

Some of the ideas that they use are attempts at one size fits all, and often don't help.

I have opened all my lockshield valves completely, set the CH water temp to 45C which keeps my return temperature in the condensing range all the time.
The only drawback is that it takes longer to get the house up to temperature in the mornings.

The new thermostat also causes it to take longer, but it does completely eliminate overshoot, and it turns on occasionally to prevent the temperature falling to the temperature at which it would normally start heating again.
The result is the temperature stays constant, avoiding the 1-2C cyclic rise and fall that makes you think it is getting cold

Keeping the return temperature within the fully condensing range is saving 7-10% gas, and the "intelligent" thermostat is saving about the same, plus the heating is on the 3 hours longer each day.

The radiators don't get hot, can easily hold them at their hottest, and they rarely get completely cold.

The only way I could get further improvement would be external wall insulation. Others round here paid 6-8000 for it.
I won't live long enough to get much of that back in gas savings

Overall though, much more comfortable, with some savings.

I've checked the manual and I believe it's the Central Heating Flow Temperature. I'm sure it changes depending on what the boiler is doing. I've no idea if that's a good temperature to keep it at! lol

 

[Mr Bump]

I'll crank it up to the max and give the HW a flush. Might be beneficial for the drains as well. Speaking of which, a drainage guy we had out recommended Fairy Liquid once in a while to help keep the drains clear - he was specific that it must be the original green stuff. Apparently there's a chemical in it that is not in their newer lines. I guess it makes sense as it's supposed to dissolve grease. Sorry, going off topic now.

yeah spot on with the fairy liquid, our kitchen sink drains into an old celler pipe which is quite long, once a year i dump about 3 litres of fairy down the sink let it sit overnight and then flush it through.

 

[Mr Bump]

I've checked the manual and I believe it's the Central Heating Flow Temperature. I'm sure it changes depending on what the boiler is doing. I've no idea if that's a good temperature to keep it at! lol

when our combi is not running the number displayed on the front is the central heating circuit temperature so at the moment its saying 25 as our heating hasn't been on since last night.
I think if it dips below 20 the combi will run the central heating pump briefly just to check its frost setting

 

[gman]

when our combi is not running the number displayed on the front is the central heating circuit temperature so at the moment its saying 25 as our heating hasn't been on since last night

I reckon I'll need to investigate mine further. I don't like the radiators being too hot as it's an uncomfortable heat as it moves to the thermostat value and I feel like there's overshoot. But if they aren't warm enough it feels like the heating is on all the time.

 

[Mr Bump]

I reckon I'll need to investigate mine further. I don't like the radiators being too hot as it's an uncomfortable heat as it moves to the thermostat value and I feel like there's overshoot. But if they aren't warm enough it feels like the heating is on all the time.

FLOW temperature is different that is when the heating is running the max the boiler will keep the heating circuit at. When our heating starts running you can then adjust that setting but only when its running on our combi I have mine set at 70 degrees this is when the whole condensing thing and laddering come into play.as above if your house is very well insulated you can have this quite low in the 50s degs but our old victorian terrace needs more heat to keep some of our bigger rooms warm.

 

[gman]

We are insanely insulated at the roof level and upper floor level, but unfortunately, on the ground floor I didn't seal the floorboard gaps because I wanted airflow and I think the cold does come in through here.

 

[Mr Bump]

We are insanely insulated at the roof level and upper floor level, but unfortunately, on the ground floor I didn't seal the floorboard gaps because I wanted airflow and I think the cold does come in through here.

one of our biggest issues as well, all the ground floor of our house has full cellers and wooden floors.....brrrr
If i was going to stay in the house much longer i would insulate the floor but we are selling up next year

 

[Sangoma]

FLOW temperature is different that is when the heating is running the max the boiler will keep the heating circuit at. When our heating starts running you can then adjust that setting but only when its running on our combi I have mine set at 70 degrees this is when the whole condensing thing and laddering come into play.as above if your house is very well insulated you can have this quite low in the 50s degs but our old victorian terrace needs more heat to keep some of our bigger rooms warm.

At 70C it is probably well outside the condensing range.

 

[Sangoma]

I reckon I'll need to investigate mine further. I don't like the radiators being too hot as it's an uncomfortable heat as it moves to the thermostat value and I feel like there's overshoot. But if they aren't warm enough it feels like the heating is on all the time.

Yes, a cooler radiator temperature will mean they stay on longer, but there will be time for temperatures to even out, and less overshoot.

Ignoring losses, it will take the same amount of energy to has a room by 5C, whether done slowly or quickly.

 

[gman]

Yes, a cooler radiator temperature will mean they stay on longer, but there will be time for temperatures to even out, and less overshoot.

Ignoring losses, it will take the same amount of energy to has a room by 5C, whether done slowly or quickly.

Been having a little look online and it seems the ideal return temp (if getting 20°C loss from the radiators) to be 45°C, so exit temp needs to be around 65°C?

 

[Mr Bump]

Been having a little look online and it seems the ideal return temp (if getting 20°C loss from the radiators) to be 45°C, so exit temp needs to be around 65°C?

its an odd one how to work it out but soounds about right

 

[Mr Bump]

At 70C it is probably well outside the condensing range.

if the output is any lower my old house simply will not warm up enought 1895 old Victorian Terrace full height ceilinge etc. I tried it at 65 a while ago and just not enough heat got to the other rooms before the thermostat in the main lounge reached heat.

Vailant say for mine ecopro 28

For a modern combi boiler, the radiator heating temperature should be set for a flow temperature of between 60 and 70°C. Any higher than this and the boiler won’t enter condensing mode and be at its optimum efficiency and performance.

 

[gman]

if the output is any lower my old house simply will not warm up enought 1895 old Victorian Terrace full height ceilinge etc. I tried it at 65 a while ago and just not enough heat got to the other rooms before the thermostat in the main lounge reached heat.

Vailant say for mine ecopro 28

For a modern combi boiler, the radiator heating temperature should be set for a flow temperature of between 60 and 70°C. Any higher than this and the boiler won’t enter condensing mode and be at its optimum efficiency and performance.

Ahhh, I was wondering why some of the radiators upstairs and the very top one was only warm on the upper part (if lower I would have assumed air). I'm guessing my exit temp isn't high enough!

 

[Mr Bump]

Ahhh, I was wondering why some of the radiators upstairs and the very top one was only warm on the upper part (if lower I would have assumed air). I'm guessing my exit temp isn't high enough!

in a classic heating system it shouldn't work that way as most radiators pull off the hot side and return to the cold side so technically accounting for a bit of loss of heat in pipes all rads should reach top temp , maybe yours need bleedin

 

[Sangoma]

if the output is any lower my old house simply will not warm up enought 1895 old Victorian Terrace full height ceilinge etc. I tried it at 65 a while ago and just not enough heat got to the other rooms before the thermostat in the main lounge reached heat.

Vailant say for mine ecopro 28

For a modern combi boiler, the radiator heating temperature should be set for a flow temperature of between 60 and 70°C. Any higher than this and the boiler won’t enter condensing mode and be at its optimum efficiency and performance.

It is not the "flow" (by that I assume you mean the temperature of the heating water leaving the boiler) temperature that determines whether the boiler operates in condensing mode or not, it is the return temperature that is important, and usually they start to loose efficiency above about 37C return temperature.

"

I tried it at 65 a while ago and just not enough heat got to the other rooms before the thermostat in the main lounge reached heat"

then reduce the flow through the lounge radiator/s
Do the same in other rooms that get too warm, or fit thermostatic radiator valves.

You can do this with the ordinary valves on the radiator, or you can reduce the flow with the lockshield valve, then make fine adjustments with the "left hand" one.

Take some time over it and get all the rooms heating about evenly (don't "balance" the system, only works in a perfect setup)

Once you have done that, then measure the return temperature to the boiler (usually the right hand side thick pipe) and adjust your heating water temperature down until it is as near as possible to 37C

Yes, it will take longer to warm the house from cold, but once warm it will be more stable and using less fuel.

 

[Mr Bump]

@Sangoma nah too much hassle plus when i put the heating on i want the house warm quick.
I'm not that fussed about the gas bill to be honest

 

[gman]

in a classic heating system it shouldn't work that way as most radiators pull off the hot side and return to the cold side so technically accounting for a bit of loss of heat in pipes all rads should reach top temp , maybe yours need bleedin

Bleeding was the first thing I checked as it did need bled in the distant past, but they were fine. I would have expected the opposite if they needed bleeding (cold on top instead). I'll raise the temp and check.

 

[Mr Bump]

Bleeding was the first thing I checked as it did need bled in the distant past, but they were fine. I would have expected the opposite if they needed bleeding (cold on top instead). I'll raise the temp and check.

might be valve balance as well, pipes are funny things and water will take the path of least resistance are both sides of the rad fully open

 

[gman]

might be valve balance as well, pipes are funny things and water will take the path of least resistance are both sides of the rad fully open

Aye and it's a fairly new radiator (about 7 years old). I'll see what happens after I increase the temp a little.

 

[Sangoma]

Ahhh, I was wondering why some of the radiators upstairs and the very top one was only warm on the upper part (if lower I would have assumed air). I'm guessing my exit temp isn't high enough!

Check the lockshield valves are not shut or nearly closed

 

[gman]

Check the lockshield valves are not shut or nearly closed

If it's the temp valve thingy that controls the flow then it's fully open. If it's something else, I'm gonna need directions lol

 

[Mr Bump]

If it's the temp valve thingy that controls the flow then it's fully open. If it's something else, I'm gonna need directions lol

no its the valve on the other side of the rad the temp thing controls the flow in, but if the out valve is closed or restricted then you can only get so much flow, hope that makes sense

 

[Sangoma]

If it's the temp valve thingy that controls the flow then it's fully open. If it's something else, I'm gonna need directions lol

It will have a plastic cap on it with a screw in the top, (unless it has been left off or snapped off)
Remover the screw and it will reveal a square shaft (about 6mm) which you turn like a tap, probably with a small shifting spanner, or a set spanner if you have the right size.

They are normally used for balancing the system, ie making sure you have the same degrees temperature drop between the in and out of every radiator. Usually 12C.
However that drop will depend on the temperature of the house, and the system temperature.

It is a good starting point if the user doesn't want to or can't make any other adjustments, and allows the normal valves to make adjustments in either direction, but assumes a "perfect" system. It falls down like the above case where the lounge got to hot, the thermostat was in the lounge and shut down before the rest of the house was warm.

I think the best way is lockshields wide open and thermostatic valves on all radiators, and second best (because it is quicker ) is all open, then use them to restrict the flow on the rooms that get too hot.

 

[Mozthecat]

Stupid question(based on experience with a colleague so not asuuming! ) but it is a wired thermostat in the living room, rather than a wireless one that could be moved to one of the cooler room?

 

[Sangoma]

Stupid question(based on experience with a colleague so not asuuming! ) but it is a wired thermostat in the living room, rather than a wireless one that could be moved to one of the cooler room?

Not a stupid question at all, and even if it was wired it is inexpensive to fit a wireless one, and fit an "intelligent" one will help save

 

[gman]

no its the valve on the other side of the rad the temp thing controls the flow in, but if the out valve is closed or restricted then you can only get so much flow, hope that makes sense

It will have a plastic cap on it with a screw in the top, (unless it has been left off or snapped off)
Remover the screw and it will reveal a square shaft (about 6mm) which you turn like a tap, probably with a small shifting spanner, or a set spanner if you have the right size.

They are normally used for balancing the system, ie making sure you have the same degrees temperature drop between the in and out of every radiator. Usually 12C.
However that drop will depend on the temperature of the house, and the system temperature.

It is a good starting point if the user doesn't want to or can't make any other adjustments, and allows the normal valves to make adjustments in either direction, but assumes a "perfect" system. It falls down like the above case where the lounge got to hot, the thermostat was in the lounge and shut down before the rest of the house was warm.

I think the best way is lockshields wide open and thermostatic valves on all radiators, and second best (because it is quicker ) is all open, then use them to restrict the flow on the rooms that get too hot.

Ah ok thanks. From memory I think it's an exposed nut on this specific radiator. I'll grab a photo at some point. The other radiators in the house are rather old, so I'm not particularly keen to start messing with them! lol

 

[gerry s]

If your radiators were fitted at the time original boiler was installed then your radiators will not achieve desired temperatures at lower flow temperatures. They would probably be sized up using delta t50 and if you want to use lower boiler flow temperatures (t30) they would have to be resized.
Boilers start condensing at return temperatures of about 55 and lower. The lower the temperature the more they condense.
Forgot to say the most common cause of radiators being cold at the bottom is sludge. Best attended to sooner rather than later. If you have a new boiler this should have been attended to during installation.

 

[gman]

If your radiators were fitted at the time original boiler was installed then your radiators will not achieve desired temperatures at lower flow temperatures. They would probably be sized up using delta t50 and if you want to use lower boiler flow temperatures (t30) they would have to be resized.
Boilers start condensing at return temperatures of about 55 and lower. The lower the temperature the more they condense.
Forgot to say the most common cause of radiators being cold at the bottom is sludge. Best attended to sooner rather than later. If you have a new boiler this should have been attended to during installation.

Sludge did cross my mind, but the boiler is only about 11 years old, it's got one of those magnaclean filters that is serviced every year and the radiator in question is only about 7 years old. It's fully hot now that I've turned the CH temp up.

 

[gman]

Here's the other side of that radiator. Just checked and it's roasting hot all over so hopefully it wasn't sludge but just the boiler output not high enough.

 

[Sangoma]

Here's the other side of that radiator. Just checked and it's roasting hot all over so hopefully it wasn't sludge but just the boiler output not high enough.

View attachment 408256

It's good that it is working, as that is what counts.
I have no idea why that radiator did not get hot, just questions

Why did that one not get hot, and the others did?

What diameter is that white pipe, and are all the other radiators fitted with the same size?
It is very hard to judge the size of the pipe, but is yours a micro-bore system?

The worst that could result from turning it up is an extra 25-35p a day costs

 

[gman]

It's good that it is working, as that is what counts.
I have no idea why that radiator did not get hot, just questions

Why did that one not get hot, and the others did?

What diameter is that white pipe, and are all the other radiators fitted with the same size?
It is very hard to judge the size of the pipe, but is yours a micro-bore system?

The worst that could result from turning it up is an extra 25-35p a day costs

I'm guessing it may have struggled due to being at the top of the house? It's 10mm, the rest of the house is 8mm. All seems good now, so happy! Cheers

 

[Sangoma]

I'm guessing it may have struggled due to being at the top of the house? It's 10mm, the rest of the house is 8mm. All seems good now, so happy! Cheers

Maybe, but why should hotter water flow there when the other didn't? Possibly the way it is connected, the water has been cooled by another radiator first?

OK, it was only after your photo that I suspected you might have a microbore system, I don't remember seeing it mentioned before, my apologies if it was.

I have had very little experience of it, but I do know that some settings need to be different, temperature differentials are different, and radiator sizes are often different.
The only thing I am sure remains the same is the boiler return temperature needs to be in the same range for the boiler to operate in condensing mode.
Because of the difference in flow rates, it is probably not valid to compare the CH water temperature at the boiler with a system that has the normal 15mm pipes

 

[gman]

Maybe, but why should hotter water flow there when the other didn't? Possibly the way it is connected, the water has been cooled by another radiator first?

OK, it was only after your photo that I suspected you might have a microbore system, I don't remember seeing it mentioned before, my apologies if it was.

I have had very little experience of it, but I do know that some settings need to be different, temperature differentials are different, and radiator sizes are often different.
The only thing I am sure remains the same is the boiler return temperature needs to be in the same range for the boiler to operate in condensing mode.
Because of the difference in flow rates, it is probably not valid to compare the CH water temperature at the boiler with a system that has the normal 15mm pipes

I'll get my probe on the return pipe and see what it says.

But aye, tiny pipes. When doing renovations downstairs and trying to disconnect a radiator the daft wee pipe split and being 8mm he didn't have a stop end to hand. That wasn't fun.