Automatic Bypass Valve .. CLARIFICATION

[fuzzy]

I know that fuzzy but someone was saying theres no point installing an auto bypass if you have a rad as a bypass. Just spoke to a heating engineer who told me the same thing. But what if someone turns the rad off and there is no bypass? Surely there should be an auto bypass on every new install???

correct

 

[Billy Bob Bob]

its not really automatic it bypasses trough the plate heat and baxi have used a 10mm pipe idea as far back as the first 80 and 105 e,i am with puddle on one rad without a trv always needs to be left off in the room with a roomstat other wise they work against each other

 

[gti8vdave]

Hi Guys,

Need you're expertise please.

My heating system is very basic I don't have a termostat, all I have is a knob on the boiler to turn the heat up on the water.


This was a problem as in the morning I needed the heating on but also the hot water for a shower. But because the central heating water heats the water in my hot water cylinder means i have to crank my boiler up but in turn means my rads go red hot as they didn't have any controls on them except the lounge.

I have five rads in my house 2 x bedrooms, 1 x bathroom, 1 x lounge and 1 x kitchen. I have since fitted two drayton trv4's on the bedrooms the bathroom rad is turned off, the lounge rad has an old fashioned knob which you can turn up and down and the kitchen rad is the same as the bathroom but the valve is constantly stuck on.

I want to fix the Kitchen rad by putting another Drayton TRV4 on but looking around the net i have seen people saying that if you have trv's fiited you need to fit an automatic by pass valve, however I have also read that you can get away without fitting a bypass valve if you leave one rad without a trv to maintain the flow of water although it is not an economical solution.

I was thinking in my case this could work for me because i could stick a TRV on the kitchen rad and then leave the bathroom rad on which would kind of act as a bypass valve.

My only other idea would be to fit a basic thermostatic valve to the rad in the kitchen which i am thinking i should have done at the beginning with the two bedroom rads and taking the trv's off the bedroom rads and replacing those with basic valves too. or fitting a bypass valve.

my boiler is a 1998 glow worm ultimate basic jobbie, please could you confirm the above, I have spent alot researching this on the net and have found nothing so I am thinking there will be alot of people out there which would benefit from this question.

Many Thanks. D

 

[Halesowen1]

You will be fine with just leaving the one rad left open and put TRV's on the others.
But remember the rads will still get as hot, they dont reduce the temp of the water they will just stop that warm now untill they reach the setting you leave them on, which at that point they will shut off.

 

[Simon F]

getting a room thermostat fitted would be better, usually hallway/lounge. that area would not want a trv. what controls does the system have, zone valves, cylinder stat, programmer etc.Depending how things are currently set up would determine what work was involved. but with a few changes to controls and maybe pipe work, you could have full control of your heating.

 

[Hardy1]

yep-no TRV in room containing Room thermostat.

 

[gti8vdave]

Ok cheers guys, thanks for all you're help.

Regards

D

 

[shahmk]

Netaheat bypass advice required:

I have a Netaheat Electronic 16/22 boiler with a manual gate valve bypass for the pump over-run between the flow and return after the pump but before either zone valves. The boiler will hopefully be changed for a Worcester Bosch Greenstar 24Ri High Efficiency Boiler towards the end of this summer.

In the meantime I want to fit a Honeywell automatic bypass valve to replace the manual one, but am confused which one to use, DU144 or DU145. There are presuure and capacity differences between the 2 as well as one being angled and one straight. Could someone please advise as to which will be suitable for both boilers so as to minimise the work during the boiler change.

Thank You.

 

[Simon F]

Hello shahmk,
I would wait, why go to the bother of draining and filling the system twice.
fitting the bypass when doing the boiler will not be a big job.

 

[Inverness]

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.

 

[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