Three port valve question

[kevindgas]

great physics lesson guys but the real issue is that the op's system won't work correctly with a y plan valve in the system

 

[seco services]

yes and you told him that.
then we had to give a d*ckhead a lesson on 3 port valve workings.

 

[matt1e]

great physics lesson guys but the real issue is that the op's system won't work correctly with a y plan valve in the system

presisely
it does not matter on the wiring issues the real problem is a 3port allways has a port open in any position

 

[picasso]

depends on how its plumbed up, you dont need a 2 port valve to control the ufh,so if the installer has put in a 2 port before the 3 port this will stop unwanted heating of the cylinder/rads when the ufh is running.

 

[kevindgas]

depends on how its plumbed up, you dont need a 2 port valve to control the ufh,

utter rubbish!! unless you use a zone valve on each circuit there is nothing to stop the flow being drawn through that circuit when another is running (you would have a similar effect as you get in a gravity hot water circuit)

 

[APHSLTD]

yes and you told him that.
then we had to give a d*ckhead a lesson on 3 port valve workings.

And yeh still got it wrong c*cksucker

 

[APHSLTD]

go read how a y plan 3 port valve works.
the grey wire will hold the valve in last position of what ever was last calling for heat.

don't come back till you have read how they work.

Tell him Seco

Close but no cigar

If the cylinder stat is satisfied and the heating shuts off, leaving 240vac on the grey wire the MV will stay in the last position.

But if the last call was HW then the valve will stay in HW regardless of the grey wire. So the grey wire does not hold the valve in the last position of whatever last called for heat. It will hold the valve in CH if CH was last to call for heat.

 

[kevplumb]

depends on the type of valve FFS

 

[doitall]

go read how a y plan 3 port valve works.
the grey wire will hold the valve in last position of what ever was last calling for heat.

don't come back till you have read how they work.

Tell him Seco

Close but no cigar

If the cylinder stat is satisfied and the heating shuts off, leaving 240vac on the grey wire the MV will stay in the last position.

But if the last call was HW then the valve will stay in HW regardless of the grey wire. So the grey wire does not hold the valve in the last position of whatever last called for heat. It will hold the valve in CH if CH was last to call for heat.

If the cylinder stat is satisfied and the heating shuts off, leaving 240vac on the grey wire the MV will stay in the last position.

Read it again, stay in the last position, therefore if the last position is HW it will stay in HW

 

[seco services]

now your sure its last position. is that what your saying ?

 

[picasso]

depends on how its plumbed up, you dont need a 2 port valve to control the ufh,

utter rubbish!! unless you use a zone valve on each circuit there is nothing to stop the flow being drawn through that circuit when another is running (you would have a similar effect as you get in a gravity hot water circuit)

I take it you dont install ufh then! what do you think the actuators are for? on many ufh systems the thermostats control the actuators which (through a relay )switch on the boiler, the 2 port valves are used to block any zones not needed, when a three port valve is used for rads/cylinder a blocking 2 port valve has to be used because 1 of the ports on the 3 port is always open . sheeeeeesh.

 

[kevindgas]

I take it you dont install ufh then! what do you think the actuators are for? on many ufh systems the thermostats control the actuators which (through a relay )switch on the boiler, the 2 port valves are used to block any zones not needed, when a three port valve is used for rads/cylinder a blocking 2 port valve has to be used because 1 of the ports on the 3 port is always open. sheeeeeesh.

waste of time fitting a mid position valve then !!! 2 zone valves are cheaper than a zone valve and a mid position as well.

 

[picasso]

[/quote]

waste of time fitting a mid position valve then !!! 2 zone valves are cheaper than a zone valve and a mid position as well. [/quote]

bit of a difference from "utter rubbish", if the 3 port is there to begin with its cheaper to just install a 2 port as a blocker, maybe the op (remember him?) has this set up.

 

[kevindgas]

Hi,

I have a three-zone system, one HW, one radiator CH, and one zone underfloor heating (ground floor). The HW and CH are controlled by a 3-way valve, the UFH by a separate 2-way valve. It's all working fine, though was only installed a week or two ago.

yes i remember the OP unlike you. was that your best shot

 

[picasso]

I am not trying to shoot you , the op can see the valves but I am not sure that he under stands exactly what each valve is doing (could be totally wrong of course) it could be the 2 port letting by, it depends on how his system is plumbed up.