Boiler and room stat settings?

kwikbreaks

He clearly believes that a thimbleful of hot water is sufficient to heat a room. Somebody who fails to comprehend the difference between heat and temperature isn't worth wasting time on so just ignore him.

Mr_Ted

kwikbreaks wrote: »

He clearly believes that a thimbleful of hot water is sufficient to heat a room. Somebody who fails to comprehend the difference between heat and temperature isn't worth wasting time on so just ignore him.

:rotfl:OK the FACTS, as clearly you do NOT comprehend :mad:

A lockshield is used to balance the circuits by restricting the flow to rads and to assist with energy efficiency by returning any excess heated water via the pipework to the boiler so that the boiler shuts off at the desired set temperature, and thereby the boiler just fires to keep the heat in the circuits topped up to replace that dissipated into the room, FACT

By restricting a lockshield it only slows the rate at which the heated water circulates through the rad, THAT water WILL be at the temperature as set by the boiler stat setting once the system has reached temperature, thereby once the rad is hot IT WILL REMAIN at that temperature, thereby heating the room in accordance with the output of the radiator, or by the operation to control that temperature by any form of thermostat within that space, FACT

If no TRV is fitted and a wheelhead valve is then the rad will work in exactly the same way no matter how much it is turned down, UNLESS THE VALVE IS TURNED OFF COMPLETELY, FACT

If a TRV is fitted then that will modulate the flow of water through the rad in accordance with the temperature setting that is desired for the room by adjusting the themostatic head, the water that flows through the rad will STILL be at the temperature as dictated by the boiler stat setting, WHEN the TRV modulates to OPEN, FACT

FACT, even if a thimblefull of water flows through the rad it WILL eventually mean the rad WILL reach the temperature of the water in the system, as it is is extremely unlikely that the heat will be dissipated from the rad quickly enough to keep the rad cooler, thereby the room WILL be heated to the output as designed by the size of the rad in accordance to its relative thermal design output

Systems and ALL component parts operate on what they are designed to do and what they are set to do, which you clearly do not comprehend;)

southcoastrgi

Well Mr T you are patience, personally I can't be arsed replying to a number of people on here who haven't got the first clue what they are talking about when it comes to heating systems

sk240

You really dont know what you are talking about, you can easily close off a lockshield valve substancially cutting down its output without turning it off completely if a TRV is not installed.

The lockshield is there so that you can balance the radiators so that you only get the amount of hot water to the rad that i can dissipate in heat.
You also balance it so thet only cool water is returned back to the boiler, the usual stated numbers are 50'C in and 30'C out for maximum efficiency, a boiler cannot heat up already hot water.
In fact if your boiler is cycling, then the system is not ballanced correctly and is receiving hot water back causing it to shut off. if it is setup correclty only the wall thermostst or timer shoud cause it to turn off.

Mr_Ted wrote: »

:rotfl:OK the FACTS, as clearly you do NOT comprehend :mad:

A lockshield is used to balance the circuits by restricting the flow to rads and to assist with energy efficiency by returning any excess heated water via the pipework to the boiler so that the boiler shuts off at the desired set temperature, and thereby the boiler just fires to keep the heat in the circuits topped up to replace that dissipated into the room, FACT Not Fact

By restricting a lockshield it only slows the rate at which the heated water circulates through the rad, THAT water WILL be at the temperature as set by the boiler stat setting once the system has reached temperature, thereby once the rad is hot IT WILL REMAIN at that temperature, thereby heating the room in accordance with the output of the radiator, or by the operation to control that temperature by any form of thermostat within that space, FACT Not Fact

If no TRV is fitted and a wheelhead valve is then the rad will work in exactly the same way no matter how much it is turned down, UNLESS THE VALVE IS TURNED OFF COMPLETELY, FACT, Not Fact

If a TRV is fitted then that will modulate the flow of water through the rad in accordance with the temperature setting that is desired for the room by adjusting the themostatic head, the water that flows through the rad will STILL be at the temperature as dictated by the boiler stat setting, WHEN the TRV modulates to OPEN, FACT Not Fac the supplied water will be at the boiler setpoint, but the radiator wont if it has restricted flow.

FACT, even if a thimblefull of water flows through the rad it WILL eventually mean the rad WILL reach the temperature of the water in the system, as it is is extremely unlikely that the heat will be dissipated from the rad quickly enough to keep the rad cooler, thereby the room WILL be heated to the output as designed by the size of the rad in accordance to its relative thermal design output Not Fact

Systems and ALL component parts operate on what they are designed to do and what they are set to do, which you clearly do not comprehend;)

malc_b

OK, as there seems to be a bit of misinformation here I have a go.

1. TRVs and lockshields are different. You use lockshields to balance the flow so that each radiator gets its fair share. That way all the rooms of a house heat up when you turn the CH on in the morning. If you relying on TRVs to balance then one room heats up first (the one with the most flow) then the next and so on.

2. Flow rate is import. A boiler dumps say 8400 W in to the water. The temperature rise across a boiler is 10C, that means the flow rate is 0.2 l/s (water is 4200 J/l, 1J = 1W per second). And the reverse is true so a radiator with a 10C drop, in to out, and a flow of 0.01 l/s is dumping 420W to the room. Assuming this is a "420W" rad then it will be at 60C above ambient, so 65C in, 55C out, water. If the flow is 0.001 l/s then the rad output is 42W, the rad will be ~10C above ambient. Hence it's not correct to say however low the flow the rad will still get hot.

3. The most efficient point for a condensing boiler to operate is reckoned to be 55C return water temperature. Boiler thermostat should be set to give that (so 65C out, if boiler flow is set to 10C drop). This might result in HW cylinder being too cool to meet legionaire recommendation of 60C). In cold weather you may need to increase CH time or increase thermostat (time may be cheaper as non-condensing loses ~10%). Note this only applies to modulating gas (oil is on/off).

Mr_Ted

sk240 wrote: »

You really dont know what you are talking about, you can easily close off a lockshield valve substancially cutting down its output without turning it off completely if a TRV is not installed.

The lockshield is there so that you can balance the radiators so that you only get the amount of hot water to the rad that i can dissipate in heat.
You also balance it so thet only cool water is returned back to the boiler, the usual stated numbers are 50'C in and 30'C out for maximum efficiency, a boiler cannot heat up already hot water.
In fact if your boiler is cycling, then the system is not ballanced correctly and is receiving hot water back causing it to shut off. if it is setup correclty only the wall thermostst or timer shoud cause it to turn off.

Total balderdash :rotfl::rotfl::rotfl:

Mr_Ted

malc_b wrote: »

OK, as there seems to be a bit of misinformation here I have a go.

1. TRVs and lockshields are different. You use lockshields to balance the flow so that each radiator gets its fair share. That way all the rooms of a house heat up when you turn the CH on in the morning. If you relying on TRVs to balance then one room heats up first (the one with the most flow) then the next and so on.

2. Flow rate is import. A boiler dumps say 8400 W in to the water. The temperature rise across a boiler is 10C, that means the flow rate is 0.2 l/s (water is 4200 J/l, 1J = 1W per second). And the reverse is true so a radiator with a 10C drop, in to out, and a flow of 0.01 l/s is dumping 420W to the room. Assuming this is a "420W" rad then it will be at 60C above ambient, so 65C in, 55C out, water. If the flow is 0.001 l/s then the rad output is 42W, the rad will be ~10C above ambient. Hence it's not correct to say however low the flow the rad will still get hot.

3. The most efficient point for a condensing boiler to operate is reckoned to be 55C return water temperature. Boiler thermostat should be set to give that (so 65C out, if boiler flow is set to 10C drop). This might result in HW cylinder being too cool to meet legionaire recommendation of 60C). In cold weather you may need to increase CH time or increase thermostat (time may be cheaper as non-condensing loses ~10%). Note this only applies to modulating gas (oil is on/off).

........................................................................

Mr_Ted

southcoastrgi wrote: »

Well Mr T you are patience, personally I can't be arsed replying to a number of people on here who haven't got the first clue what they are talking about when it comes to heating systems

Yes I wonder myself, but, so much crap is talked here by those that really dont know, it would be unfair to the OP's to not say something

Its bad enough we have qualified individuals out there giving the industry a bad name and the authorities not doing enough to curtail them, employers in the interest of their profit encouraging the bad practices by not fulfilling their obligations to conform to good practices, and customers so interested in saving a few pennies they cant be bothered to find out the true facts of who they employ or the actual problem they have and how to fix it :eek:

The fact is, I have seen it so many times, and tried to do something about it, when I have had the authority, AND I HAVE, but also suffered because I am conscientious about my trades and experience.
Its because employers, and individuals, WONT accept that the only way to do a job is the RIGHT way 1st time, and they would rather ignore the bad practices for fear of their reputation, and the fact they would rather ignore going back or admitting mistakes, that they dont actually understand its because they ignore this that they do get a bad reputation :mad:

Unfortunately, no one on here can actually verify who is right and who is wrong, except by trial and error, and thats not good, and its a worry that seriously bad information that could lead to an incident that will cause harm to someone is quite likely.

All I can say is that this Forum and the people who run it need to be very careful as to what they allow on here, as it is quite possible that if an event occurs due to someone using bad information posted on here, then someone is likely to be held accountable :beer:

There is of course in some cases the need to STATE THE BLEEDING OBVIOUS :rotfl::rotfl::rotfl:

espresso

Mr_Ted wrote: »

All I can say is that this Forum and the people who run it need to be very careful as to what they allow on here, as it is quite possible that if an event occurs due to someone using bad information posted on here, then someone is likely to be held accountable :beer:

Mr Ted would you care to comment on the following published by MSE Guy here:

Q. Should I turn individual radiators down at the valve or will it only make a difference if controlled via the main thermostat?

A. There's little difference. By turning your radiators down or off using thermostatic radiator valves on the side of them, or by reducing your room temperature via a thermostat, you decrease the amount of heat your heating system has to generate.

Your room thermostat only switches your heating off when the set temperature has been achieved, so turning your thermostatic radiator valves down will mean your radiators will not get as hot and will gently heat your home to the set temperature.

If you have them on high, your radiators will emit lot of heat until the set temperature is met.

malc_b

Mr_Ted wrote: »

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Does that mean you agree or disagree?

BTW there is kernel of truth in the statement "if the rad are not balanced then the boiler cycles" Of course modulating gas boilers don't cycle but if you are taking about oil or old gas (on/off types) then an unbalanced system can result in most of the flow going through just a few rads instead of all of them. Then you have say a 10kW boiler driving 2kW of rads (rather than say 5-7kW of rads). The house struggles to get warm and the boiler can't dump all its heat so ends up cycling on/off.