3/4 union fitting on old rad, new rad thermostat won't fit
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Yeah, to be fair I think I only wrapped the tape around 5 times. I've looked at the ice cream carton this morning and there's a very small amount of water in there maybe 5 drops or so. I can still see tape on the exposed threads so maybe I'll get away with tightening it up a tad more just don't want to over tighten and strip the thread.
For draining one rad down would I need to worry about adding inhibitor back into the system?
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If there is enough play on the pipework to allow you to remove the tail with the valve still in position ,you don't need to drain down. If you do drain down top up inhibitor.
Surely when I remove the tail from the rad water will start pouring out?, or with a combi is there enough presure to cause a vacuum so not much water escapes, so I have time to remove the old PTFE tap and applied new before I'm drowning in water??
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If you do not remove the valve from the pipework:
1. Turn the other end (lockshield valve) fully closed, counting the number of 1/8 turns required to close it.
2. Close the TRV.
3. Partially undo the nut connecting TRV to tail. Slowly, as water will come out.
4. Drain all water from the radiator into a tray / bucket / old towels.
5. Remove tail, clear off all old PTFE
6. Re-wrap with PTFE (15 wraps) winding in the direction that it won't unravel when you screw tail in.
7. Screw tail back in.
8. Re-tighten nut securing TRV to tail.
9. Open lockshield valve to previous position (no. of 1/8 turns)
10. Open TRV
11. Bleed radiator, topping up combi pressure as required.
12. Check for leaks.
There are alternatives to PTFE:
a. Loctite 55 is a good one, but follow the instructions, in particular make sure the threads are cleaned and you gently rough up the thread on the tail with a file. Wind on in a mixture of along the threads and across the threads. If 15 turns of PTFE is about right, 12 turns of 55 should suffice.
b. Flomasta Pipe Seal (there is a loctite equivalent) is very good, but requires both male and female threads to be very clean and grease / oil free. Just run a bead of the liquid around the second through third threads on the tail, screw in place leaving one thread showing. Sets fast so be quick. Forms a seal like a (just about) removable thread locker.
1. Turn the other end (lockshield valve) fully closed, counting the number of 1/8 turns required to close it.
2. Close the TRV.
3. Partially undo the nut connecting TRV to tail. Slowly, as water will come out.
4. Drain all water from the radiator into a tray / bucket / old towels.
5. Remove tail, clear off all old PTFE
6. Re-wrap with PTFE (15 wraps) winding in the direction that it won't unravel when you screw tail in.
7. Screw tail back in.
8. Re-tighten nut securing TRV to tail.
9. Open lockshield valve to previous position (no. of 1/8 turns)
10. Open TRV
11. Bleed radiator, topping up combi pressure as required.
12. Check for leaks.
There are alternatives to PTFE:
a. Loctite 55 is a good one, but follow the instructions, in particular make sure the threads are cleaned and you gently rough up the thread on the tail with a file. Wind on in a mixture of along the threads and across the threads. If 15 turns of PTFE is about right, 12 turns of 55 should suffice.
b. Flomasta Pipe Seal (there is a loctite equivalent) is very good, but requires both male and female threads to be very clean and grease / oil free. Just run a bead of the liquid around the second through third threads on the tail, screw in place leaving one thread showing. Sets fast so be quick. Forms a seal like a (just about) removable thread locker.
This is actually a good point and something I never considered.
So the tail will screw into the rad clockwise right as the thread is on the tail itself, so do I need to apply the tape to the tail counter-clockwise or clockwise?
Clockwise with the end of the tail towards you. That way tightening pulls the tape into the thread, ACW would push it out.
If you hold the smooth part of the tail in your left hand with the thread to the right then turn the tape onto the thread away from you - ACW
Hold the tape roll so it unwinds around the threads backhanded from the bottom of the roll.
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ACW ? Anti clockwise ?
You sure about that
Re:wrapping the ptfe... If in doubt, look on youtube for a demonstration!
You asked:
"For draining one rad down would I need to worry about adding inhibitor back into the system?"
Well, what I did recently was to capture the drained off water, filtered it through a sheet of Plenty kitchen paper in a funnel, then added it back to the header tank before refilling the rad. That way I didn't waste any inhibitor.
You asked:
"For draining one rad down would I need to worry about adding inhibitor back into the system?"
Well, what I did recently was to capture the drained off water, filtered it through a sheet of Plenty kitchen paper in a funnel, then added it back to the header tank before refilling the rad. That way I didn't waste any inhibitor.
Yup .... as it goes on the thread, it goes on away from you if you hold the tail with the thread on the right, that's, so when the tail is tightened in CW it's tightening against the tape.
Depends on what end you are looking at it from though. I'm right handed so I hold in my left and wrap with my right, as I look at it to me that's ACW.
edited to add pic
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With the threaded end facing you, the way you'd normally hold it (as I said in #22), that looks like clockwise to me. But your pic should make it clear to the OP.
Sorry but I just wouldn't hold nor ever look at it like that, hence my description. Held in my left hand with the threads to the right or right hand with the threads to the left, the tape would be going on ACW. If the tail then turns and tightens into the rad clockwise then the tape would still be running anticlockwise to ensure it doesn't unravel.
The only time it would clockwise is looking at it head on at the thread end, which is always an option and all are correct depending on the view/opinion I guess.
OK, as long as the OP understands
Hang on, thats wrapping it CW based off that picture then no? As you wrapping it away from your body not towards??. Imagine turning the tail so the thread is now facing you you'd go around with tape CW
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