central heating only comes on with h water, stumped engineer

[Mikefromlondon]

Thats interesting,

LOL, back to the drawing board!

 

[bonkersbill]

[GALLERY=media, 43386][/GALLERY] [GALLERY=media, 43387][/GALLERY] [GALLERY=media, 43388][/GALLERY] [GALLERY=media, 43389][/GALLERY]
Pictures of pipes into chimney breast, fire and boiler controls
The 28mm pipes you can see here move from left to right then bend left through the chimney breast, not too clear but i took at least 10 pics before i got one this good!
15mm D in 2nd pic is mainly hidden by the electric cable, you can just see the corroded T joint at the bottom

 

[bonkersbill]

sure you know Mike but i just want to be clear, port B is teed to middle of tank and the capped extention on top which i presume you have labled port C

 

[Mikefromlondon]

sure you know Mike but i just want to be clear, port A is teed to middle of tank and the capped extention on top which i presume you have labled port C

Thats right bill, earlier on your picture was quite misleading as I didn't expand it and only saw the pipe thats blocked off appearing like its connected to pump! my bad.

The rest of my comments have been edited as I did not want to [post misleading information.

Sorry if this may have caused any confusion to others, but i have now corrected the mistake and learnt from it, thanks everyone, resigning my post! lol

 

[doitall]

The 28mm to 22mm pipes after opening up the hole more for a better view are on top of each other going through the chimney breast, 3 test done, with programmer set to HW only, 3pv to HW the bottom 28mm pipe through the chimney and the pipe to pump gets hot before pipe out of bottom of tank, same result with prog HW&CH, 3pv HW or Mid

And was this with the pump running.

 

[D_Hailsham]

Untitled

• bonkersbill
• 29 Feb 2012
• 1

1. What is the insulated pipe coming from the top of the motorized valve (the one with a red gate valve) connected to?

2. What is the pipe coming from the bottom of the motorized valve connected to?

 

[doitall]

sure you know Mike but i just want to be clear, port A is teed to middle of tank and the capped extention on top which i presume you have labled port C

This thread is getting silly.

Can we have some straight answers please.

From the pump it goes into port AB the middle one.

Port A should go to the htg.

Port B should go to the Cylinder.

Does it or not.

 

[bonkersbill]

Sorry my mistake, top port B to cyl and bottom port A to heating, the only switch i could find which appeared to switch off the pump is on the pump

 

[UpgradeME]

for the record, 3pv valve or diverter valve you may call it, has 3 ports, port A is usually the middle port and branches off to two other ports, Port B and port C, depending how you install it, but in principle, the 3pv works by connecting port A with either port B or with port C, or in its mid position it would allow both ports connected to port A.

Mike, The OP has a Danfoss HSA3 mid position valve (as mentioned earlier in the thread! ) - The middle port is AB, the CH port is A and the HW is port B in the manufacturers instructions and on the product itself.

Sticking to a typical installaition standard helps engineers find faults quickly.

Hmm... yes, sometimes but in this case specific detailed information is what's required, not general standards.

OP, can you confirm if the pump was on or off (electrically) when you performed DIA's test please, this is important info!

 

[doitall]

Sorry my mistake, top port B to cyl and bottom port A to heating, the only switch i could find which appeared to switch off the pump is on the pump

The test is pointless with the pump running, although the result was interesting, when you say the bottom pipe gets hot first.

Remove the red wire from the pump and make it safe if you can't switch the pump off.

Turn the boiler on low and I'm willing to bet to top pipe gets hot first.

You'll only need to run the boiler for a few minutes.

In case there any confusion.

View media item 43398

 

[Mikefromlondon]

for the record, 3pv valve or diverter valve you may call it, has 3 ports, port A is usually the middle port and branches off to two other ports, Port B and port C, depending how you install it, but in principle, the 3pv works by connecting port A with either port B or with port C, or in its mid position it would allow both ports connected to port A.

Mike, The OP has a Danfoss HSA3 mid position valve (as mentioned earlier in the thread! ) - The middle port is AB, the CH port is A and the HW is port B in the manufacturers instructions and on the product itself.

Sticking to a typical installaition standard helps engineers find faults quickly.

Hmm... yes, sometimes but in this case specific detailed information is what's required, not general standards.

OP, can you confirm if the pump was on or off (electrically) when you performed DIA's test please, this is important info!

Thanks for clarifying that, I appreciate that, hence I have posted a thanks for you, as I said before its a learning curve for me as well, I had always thought they were marked individually as a,b & c

As I have no intention to upset anyone, I will let you pro guys deal with bill's problem, hopefully you will be able to resolve it soon, good luck to you all. I am resigning!! (lol)

If bill needs any assistance he can contact me via the message service, for any other help that is. i am based in london,

But I will still follow this thread as a matter of interest. There is a say, too many chefs spoil the broth!
Mike

 

[bonkersbill]

3pv is marked AB, A, B with B going to tank, A going to CH.

Test i did was remove red wire from pump, set 3pv to HW and boiler to low with prog to HW on, waited 5 mins and nothing happened, boiler had shut off, i restarted boiler and waited to see what happened, it shut off again after 1 minute, i went back upstairs but this time the pipe to the bottom of the tank was red hot and the pipe to the 3pv AB was warm to hot, sorry i missed which got hot 1st but it was unmistakable that the one to tank was hottest. Do you want me to run the test again to see which gets hot 1st?

 

[doitall]

It would confirm the primary pipes are crossed if you run the test again.

Put the mv in the mid position.

If the top pipe gets hot at the boiler then as you can see the flow is being reversed, as per my original drawing.

 

[UpgradeME]

but it was unmistakable that the one to tank was hottest. Do you want me to run the test again to see which gets hot 1st?

Can you also indicate on this drawing;

Untitled

• bonkersbill
• 29 Feb 2012
• 1

With the pump disabled
1) Which pipe(s) get hottest when with 3pv in HW position?
2) Which pipe(s) get hottest when with 3pv in HW&CH position?

With the pump enabled
3) Which pipe(s) get hottest when with 3pv in HW&CH position?

At the moment, DIA's test shows that the boiler's FLOW pipe is actually connected to the cylinder, not the pump as it should be. Questions 1&2 above are to try and work out here how many FLOW pipes there are (Looking at your drawing, I'm wondering if the top TWO 22/28mm pipes are flow, one to the cylinder and one to the CH? and the bottom one a 22mm return pipe?)

 

[doitall]

That would be an interesting thought UpgradeME

If the HTG return is not common the DHW return there will be an open circuit and the HTG should work.