Automatic Bypass Valve .. CLARIFICATION

[lame plumber]

have a long think about your question, why would you need a room stat when you could replace it with a trv?, it shows lack of knowledge and attention during lectures.

 

[Toddyplumb]

Why would you need a room stat when you could replace it with a trv,s?. For example in my house I have trv's in all my rooms and I operate the heating from my programmer. I also have an automatic bypass before the motorized valves, so when all trv's are satisfied the pressure rises then automatic bypass kicks in and protects the circulator (pump). Also the other reason why the automatic bypass is a good practice is incase the motorize valves close shut from ware and tear and the boiler is still on the flow will buildup and automatic bypass comes into action.

i am nearly finished my 1st year plumbing apprenticeship so be nice.

for exactly the reason you say , there would be nothing apart from the programmer to turn the pump off . The room stat will turn the pump off every time it is satisfied

 

[Inverness]

Using a radiator as a bypass is a good way to keep the coldest room in the house warmest with out turning off until the boiler has switch off. But using this method correctly the flow and return to this bypass rad needs to be before the motorised valves? Reason the pump will always be protected from over heating. If you had the bypass rad after the motorised valves could this be bad practise as the motorised valves could become faulty and shut off completely while the boiler is still running. the bypass radiator becomes non affected and the flow wouldn't have any where to go. But haven an automatic bypass valve fitted before the motorised valves would cover all angles and protection to pump and circulation.
I am neatly finished my first year as a plumber so be nice.

my boss never installs room thermostats and says trv's in all rooms. I also said to him trv's and room thermostats should never be in the same room as they would conflict with one another. Would the advantage of a room thermostat would be for larger area rooms that needs more heat continuously without a trv? I'm a wee bit unclear can some one explain. Thanks

 

[Simon F]

research boiler interlock, then comment!

 

[Inverness]

Toddy plumb. Thanks I'm only learning. With a room thermostat you can turn it down and this will call the boiler to shut off but with trv's all round you would need to manually turn the boiler off? What if you had trv's set on a timer from your programmer?

 

[Toddyplumb]

Well im afraid your boss is not teaching you the correct way. Ask your college lecturer and as Simon F says research boiler interlock

 

[Toddyplumb]

There is no need to manually turn off the boiler the room thermostat will do it without you having to leave your cosy armchair

 

[Inverness]

What about the programmers that have a built in room thermostate? Maybe I'm confused.
Can you explain boiler interlock? Thanks for replying

 

[Aquazone]

If you mean a programmable room stat, then yes, that would be OK as a control.

Boiler interlock is basically a series of controls that will shut the boiler and pump off when a set temperature is reached.

Eg - room stat gets up to temp, which then kills power to motorised valve, valve denergises and kills power to boiler SwL and PcB kills power to pump after overrun.

 

[dancinplumba]

Something that turns off boiler when there is no heat demand ie room stat

 

[Inverness]

So by having a room stat you could set it for 21' and once the boiler has reached that temperature it will shut off automatically? I understand the boiler interlock now it's a regulation that all new boiler installations 2009 need to have a boiler interlock.
By having a programmer and trv's in a house there is still boiler interlock as I need to manually adjust the temperature then the boiler reaches it then turns off? I'm I right? This is the types of systems my boss fits.are they good?

 

[Toddyplumb]

I think you are getting confused or are calling a Programmable room themostat a programmer

 

[dancinplumba]

So by having a room stat you could set it for 21' and once the boiler has reached that temperature it will shut off automatically? I understand the boiler interlock now it's a regulation that all new boiler installations 2009 need to have a boiler interlock.
By having a programmer and trv's in a house there is still boiler interlock as I need to manually adjust the temperature then the boiler reaches it then turns off? I'm I right? This is the types of systems my boss fits.are they good?

Boiler temp is not room temp

 

[pipeline]

apparently new boilers have modulating burners, and specifies that an automatic bypass are not fitted... ?

 

[dancinplumba]

Really ? You got a link ? Its nothing to do with burner, its for pump and dissipation of heat from boiler

 

[lame plumber]

Really ? You got a link ? Its nothing to do with burner, its for pump and dissipation of heat from boiler

da da too late

 

[dancinplumba]

da da too late

? For what ? Your bedtime

 

[lame plumber]

? For what ? Your bedtime

saying the same as you and bedtime

 

[pipeline]

i havn't got a link but this is what is says in the city and guilds text book..

'' install an automatic bypass valve where manufactures instructions advise installation of a bypass.. TACMA does not recommend the installation of a bypass valve if the boiler is of a fully modulating type''..

im guessing its because the flame dies down when its reaches temperature, there for the bypass wont open.. but thats only my opinion.

 

[Ermintrude]

Bypass is on pressure from pump me old chuff a. The idea is that the bypass opens as other controls on the circuit close down. Allowing a constant flow through boiler. If you don't cool the boiler after the flame has gone out it will Look like a scots bonce

 

[lame plumber]

all part of building regs now as well

 

[pipeline]

myself personally,, i would fit a bypass because it just makes scene, also the bypass would make the system more efficient as it would, interlock quicker or turn off quicker, but then they say not to fit them if the boiler is of a modulating type,, its all a bit confusing,, maybe some can explain this modulating thing to me. thanks

 

[Ermintrude]

Is this not a modulating pump? Not a modulating boiler?

 

[lame plumber]

modulating pumps are fine till you switch em back on manual as they fail to work properly on an old system full of muck and then is when you need you bypass again

 

[pipeline]

it actually says boiler but they could be referring to the pump,, i mentioned it because, i thought some1 could shed some light on the area 4 me. thanks