Flow Temperature or Thermostat or TRV or Lockshield Valve?

FreeBear

bob2302 said:

FreeBear said:

bob2302 said:

jennifernil said:

One thing to understand when using a thermostat as well as TRVs is that when the room where the thermostat is situated gets to the set temperature, the boiler will be turned off even though one or more of the other rooms may not have reached the temperature set on their TRVs.   

That that could be avoided by rebalancing the valves.

As long as the radiator is appropriately sized for the room.

Got one room here with an (on paper) oversized radiator. System properly balanced, yet still can't get the temperature up to a comfortable level.

Self-evidently they aren't balanced properly, or this wouldn't happen. There is a difference between radiators being correctly balanced, and correctly following a methodology intended to balance them.

Temperature curves tell a different story. All rooms heat up at a very similar rate, its just that this one room remains consistently colder.

bery_451

Reed_Richards said:

bery_451 said:

Reed_Richards said:

bery_451 said:

Reed_Richards said:

False.  The lockshield valve controls the maximum water flow rate through the radiator (at any given pump speed).  
 

To clarify for better understanding each rad has 2 copper pipes connected to it. The one that goes into the TRV is that the flow pipe (bring water into the rad) and the one connected to the lockshield valve is the return (water leaving the rad) correct? If yes then the lockshield controls the return water or is it the flow water?

By convention, the TRV is on the inlet pipe and the lockshield valve is on the outlet pipe but it doesn't matter if they are the other way around.  Both of them, working in combination, control the flow rate of water through the radiator.  We have told you repeatedly that water comes out of the radiator as fast as it goes in but you don't seem to be able to get your head around that idea.      

Yeah alright the TRV controls how much water goes in the Rad depending on the room temperature, whether the lockshield valve is fully opened or fully tightened water still leaves the Rad as the same rate as water going into the rad at the same time. They are both valves in sync at the same time in terms of water rate in ml or ltr entering & leaving the rad regardless of what position both of those valves are set. Is my understanding correct?

No, still wrong.  If the lockshield valve is fully tightened then there will be no water flow through the radiator and it will remain stone cold. 

Now suppose the lockshield valve is fully open and when the heating comes on the flow rate through the radiator is 10 litres per minute.  As the TRV reaches its set temperature it will start to close off its valve it and the flow rate through the radiator will drop down to near zero.

Now consider the case when the lockshield valve is half open.  Now the maximum flow rate through the radiator will be 5 litres per minute (instead of 10 litres per minute when it is fully open).  Since the heat output from a radiator is proportional to the flow rate then the the radiator will give out a maximum heat of half what it did when the lockshield valve was fully open.  As the TRV reaches its set temperature it will close off its valve and the flow rate will drop still further, further reducing the heat output from the radiator.    

I think that's where's the confusion is, when you say lockshield fully tightened 'then there will be no flow'. There's 2 copper pipes, the flow and the return correct? The flow is on the TRV side and the return is on the lockshield side correct? So if the lockshield valve controls the return water then how is it also controlling the flow water (water going int the rad) too?

bery_451

bob2302 said:

FreeBear said:

bob2302 said:

jennifernil said:

One thing to understand when using a thermostat as well as TRVs is that when the room where the thermostat is situated gets to the set temperature, the boiler will be turned off even though one or more of the other rooms may not have reached the temperature set on their TRVs.   

That that could be avoided by rebalancing the valves.

As long as the radiator is appropriately sized for the room.

Got one room here with an (on paper) oversized radiator. System properly balanced, yet still can't get the temperature up to a comfortable level.

Self-evidently they aren't balanced properly, or this wouldn't happen. There is a difference between radiators being correctly balanced, and correctly following a methodology intended to balance them.

Can millions of homes in the UK can do Balancing easily to save £££'s per year on their gas bills? I don't think the people even heard of the term balancing and I doubt British Gas or Octopus educate their customers on balancing as its not in their financial interests to do so.

For balancing the calculations needs to be right. Nobody knows how to access the hidden service menu on their boiler to set the pump speed and such and nobody has the schematics map of copper pipes in their homes to calculate which rads need balancing if copper pipes are hidden underneath floors/walls.

Also there's no indication markings on the lockshield valve which makes it more complex as you have to memorise it and record it to remind yourself. 

Also you balance between the TRV and the thermostat in what setting temp to select.

So its like driving a car with 2 or 3 separate gearboxes, and you have to balance all of them to get the speed you want. There's no 1 master gearbox or there's no smart valves that sync with the smart thermostat that do auto do all the balancing for you.

QrizB

I think that's where's the confusion is, when you say lockshield fully tightened 'then there will be no flow'. There's 2 copper pipes, the flow and the return correct? The flow is on the TRV side and the return is on the lockshield side correct? So if the lockshield valve controls the return water then how is it also controlling the flow water (water going int the rad) too?

Water is incompressible, and radiators don't stretch (unlike eg. a balloon). Radiators have two valves, and these are normally the only two openings in the radiator; it doesn't leak and you're not bleeding it.

Water can only flow into a radiator via one valve (eg. the TRV) if an equal amount of water can flow out of the radiator via the other valve (eg. the lockshield valve).

Closing the lockshield valve will stop water from leaving the radiator, which in turn prevents water from entering the radiator via the TRV.

bery_451

QrizB said:

I think that's where's the confusion is, when you say lockshield fully tightened 'then there will be no flow'. There's 2 copper pipes, the flow and the return correct? The flow is on the TRV side and the return is on the lockshield side correct? So if the lockshield valve controls the return water then how is it also controlling the flow water (water going int the rad) too?

Water is incompressible, and radiators don't stretch (unlike eg. a balloon). Radiators have two valves, and these are normally the only two openings in the radiator; it doesn't leak and you're not bleeding it.

Water can only flow into a radiator via one valve (eg. the TRV) if an equal amount of water can flow out of the radiator via the other valve (eg. the lockshield valve).

Closing the lockshield valve will stop water from leaving the radiator, which in turn prevents water from entering the radiator via the TRV.

So basically the radiator is full max of water at all times and the water in rad is either cold or hot?

FreeBear

bery_451 said: For balancing the calculations needs to be right. Nobody knows how to access the hidden service menu on their boiler to set the pump speed and such and nobody has the schematics map of copper pipes in their homes to calculate which rads need balancing if copper pipes are hidden underneath floors/walls.

You don't need a schematic of the heating system. As long as you can clip a thermometer to the pipes either end of the radiator, you can balance each one in turn. Yes, it is easier to go round adjusting them in the order that they heat up, but not absolutely necessary. As for pumps hidden inside the boiler, the manufacturers will have installation manuals available that detail how to get in to the service menu to adjust the speed.

Reed_Richards

bery_451 said:

So basically the radiator is full max of water at all times and the water in rad is either cold or hot?

Well, the radiator could contain both water and gas.  So you carefully open up the bleed valve at the top of each radiator.  If there is gas inside you will hear hissing.  When water starts to come out of the bleed valve you quickly close it off.  Then the radiator is completely full of water, which is what you want.

When your heating system is running, both the inlet and the outlet pipes will contain hot water but the pipe on the inlet side will be hotter than the pipe on the outlet side.  If you touch them carefully you may be able to feel this.      

bery_451

FreeBear said:

bery_451 said: For balancing the calculations needs to be right. Nobody knows how to access the hidden service menu on their boiler to set the pump speed and such and nobody has the schematics map of copper pipes in their homes to calculate which rads need balancing if copper pipes are hidden underneath floors/walls.

You don't need a schematic of the heating system. As long as you can clip a thermometer to the pipes either end of the radiator, you can balance each one in turn. Yes, it is easier to go round adjusting them in the order that they heat up, but not absolutely necessary. As for pumps hidden inside the boiler, the manufacturers will have installation manuals available that detail how to get in to the service menu to adjust the speed.

The default pump speed is not efficient? So is it increasing or decreasing it makes it more efficient?

bery_451

Reed_Richards said:

bery_451 said:

So basically the radiator is full max of water at all times and the water in rad is either cold or hot?

Well, the radiator could contain both water and gas.  So you carefully open up the bleed valve at the top of each radiator.  If there is gas inside you will hear hissing.  When water starts to come out of the bleed valve you quickly close it off.  Then the radiator is completely full of water, which is what you want.

When your heating system is running, both the inlet and the outlet pipes will contain hot water but the pipe on the inlet side will be hotter than the pipe on the outlet side.  If you touch them carefully you may be able to feel this.      

Alright just to confirm okay to bleed a cold radiator or hot for best results?

FreeBear

bery_451 said:

FreeBear said:

bery_451 said: For balancing the calculations needs to be right. Nobody knows how to access the hidden service menu on their boiler to set the pump speed and such and nobody has the schematics map of copper pipes in their homes to calculate which rads need balancing if copper pipes are hidden underneath floors/walls.

You don't need a schematic of the heating system. As long as you can clip a thermometer to the pipes either end of the radiator, you can balance each one in turn. Yes, it is easier to go round adjusting them in the order that they heat up, but not absolutely necessary. As for pumps hidden inside the boiler, the manufacturers will have installation manuals available that detail how to get in to the service menu to adjust the speed.

The default pump speed is not efficient? So is it increasing or decreasing it makes it more efficient?

It depends on what the default setting is and your installation.

When I first attempted to balance my radiators, I was finding that most of the lockshields had to be almost closed right down and even the smallest of tweaks would make a huge difference. Turning the pump speed down, and the lockshields could be opened up to allow water to flow, and small tweaks meant small changes in the temperature differential. With the correct flow rate set, the returning water is much cooler, so the boiler is able to condense properly (key for efficiency).

Last winter, had clouds of white "smoke" coming out of the exhaust, this year, you'd be hard pushed to see any.

bery_451 said:

Reed_Richards said:

bery_451 said:

So basically the radiator is full max of water at all times and the water in rad is either cold or hot?

Well, the radiator could contain both water and gas.  So you carefully open up the bleed valve at the top of each radiator.  If there is gas inside you will hear hissing.  When water starts to come out of the bleed valve you quickly close it off.  Then the radiator is completely full of water, which is what you want.

When your heating system is running, both the inlet and the outlet pipes will contain hot water but the pipe on the inlet side will be hotter than the pipe on the outlet side.  If you touch them carefully you may be able to feel this.      

Alright just to confirm okay to bleed a cold radiator or hot for best results?

Do it when cold - You reduce the risk of getting sprayed with hot (potentially scalding) hot water.