Another thing fixed

[HarryM1BYT]

Originally Posted by WillyHeckaslike

Never really done much plumbing work but come the new year I will be attempting to clean out our central heating system. I don't think that it was ever commissioned properly from the off and the plumber who fitted it was called back a couple of times in its early days because of the system pressure dropping. Gave up on him eventually and just kept on topping up the system via the filling loop as he showed us but it got worse over the years. It stopped working altogether a few months back after much complaining from the pump about the sludge that was building up within the system lol.

Sealed system? Even the tiniest of leaks, some invisible can cause the pressure to be lost. Frequent having to top it up will cause airiated water to be put in, rust and sludge.

If the leak(s) really cannot be found, find a means to drain the system completely and fill with air at 2bar. Air escapes much more easily than water, so you should be able to listen for leaks.

If the system is sludged up, best to take each radiator out side and give them a through flush through with water in both directions and likewise the pipe-work and the boiler.

Make sure you add inhibitor when you refill it, to prevent rust and sludge. If you are feeling flush (tic) well worth adding a TRV to all radiators except one - usually the one where the stat is located. A magnetic filter is also worth fitting especially when a modern boiler is fitted, to save the boilers narrow passages becoming blocked.

My system is now nearing 40 years of age, has always had inhibitor in and is clean as a whistle. I fitted its third replacement boiler in March and took the opportunity whilst it needed to be drained down, to add a magnetic filter, 9 TRV and swap the 3 port valve for a more modern and supposedly more reliable type.


It was fitted with an older spring return type valve actuator, which has caused me endless reliability problems over the years. I found a more modern, yet compatible actuator model from the same manufacturer, which didn't involve motor and spring, just a motor and electronics. To be sure, in case it caused any issues, I bought a second unit as a standby spare ready to fit
The TRV's are well worth while, because I can set each of the room temperatures separately, which saves quite a bit of fuel and the rooms needing more heat get more heat. I find there is also much less temperature fluctuation too, as the heating cuts in and out.

The TRV's were obtained 6 years ago, when our last boiler was installed, but I just never got the chance to fit them - I was away working

[HarryM1BYT]

Originally Posted by macafee2

Not risking the same pipe again I've used two new bits of pipe and a solder 90 degree fitting. Seemed water tight last night.

macafee2

When soldering pipe, just polish up the two surfaces with a bit of wire wool, apply some flux then heat them with a decent blow lamp until the solder melts and you see a ring of solder appear all the way around the fitting (solder ring type). Otherwise you feed solder into the joint until you see the ring (none solder ring type).



Compression fittings are weaker than the pipe or soldered joints, so will give out first when frozen. Add pipe insulation and if it is just a leg feeding the garage, fit an isolation valve so the water can be turned off in there in winter. Open the tap too, to release the pressure in the pipe, if doing that..

[macafee2]

[QUOTE=COLVERT;2698044]

Originally Posted by WillyHeckaslike

Never really done much plumbing work but come the new year I will be attempting to clean out our central heating system. I don't think that it was ever commissioned properly from the off and the plumber who fitted it was called back a couple of times in its early days because of the system pressure dropping. Gave up on him eventually and just kept on topping up the system via the filling loop as he showed us but it got worse over the years. It stopped working altogether a few months back after much complaining from the pump about the sludge that was building up within the system lol. [/QUOTE

What the system has to have, just like our cars, is an anti-freeze anti- corrosion additive.---Then, virtually no corrosion or sludge.

You plumber must have made some poor, dry, joints. A quantity of FLUX is absolutely essential when soldering the connections. It vastly reduces the surface tension of the lead solder and allows surface tension to completely fill the joints with lead.

Leaks come from poor joints made with not enough flux. Water can then leach through in dry areas where the solder has not taken.

I think some fluxes also act as a cleaner to the surfaces being soldered.

I remember my first heating system I installed. When I put the valve fittings into the radiators I just screwed them in without putting PTFE tape on the threads. I was gutted when every radiator leaked.


The gas boiler had a very small gas leak that the gas board engineer could not locate with his tester so he... scared the living daylights out of me by striking a match and offering it up to the boiler.


macafee2

[macafee2]

Best bit about installing plumbing is pipe bending. I got to be very good at it.
Best bit after installation, finding it does not leak.

If I ever do it again I'll something like this
https://www.amazon.co.uk/dp/B000XIZM...832&th=1&psc=1

macafee2

[COLVERT]

[QUOTE=macafee2;2698081]

Originally Posted by COLVERT

I think some fluxes also act as a cleaner to the surfaces being soldered.

I remember my first heating system I installed. When I put the valve fittings into the radiators I just screwed them in without putting PTFE tape on the threads. I was gutted when every radiator leaked.


The gas boiler had a very small gas leak that the gas board engineer could not locate with his tester so he... scared the living daylights out of me by striking a match and offering it up to the boiler.


macafee2

Don't know about that engineer striking a match.-----He should have been struck off.--


What an idiot !!!!---Soap solutions, that make bubbles, show where a gas leak is.

[COLVERT]

Originally Posted by macafee2

Best bit about installing plumbing is pipe bending. I got to be very good at it.
Best bit after installation, finding it does not leak.

If I ever do it again I'll something like this
https://www.amazon.co.uk/dp/B000XIZM...832&th=1&psc=1

macafee2

The DRY pressure tester would be the one to use.

Once there has been water in a system it's the devils own job to get the leaking part dry enough to re-solder it.

[macafee2]

Originally Posted by COLVERT

The DRY pressure tester would be the one to use.

Once there has been water in a system it's the devils own job to get the leaking part dry enough to re-solder it.

sorry, yes I agree. I was thinking of using the tester before filling with water.
I recall using pipe freeze kits. They create a small "block" of ice in the pipe so you can cut the pipe without water leaking out and the "panic" to complete the join before the ice block melted

I am now armed with PTFE tape and Boss white.

I'll boast one thing, my central heating installations don't creek.

macafee2

[WillyHeckaslike]

Ye Gods. I didn't expect such a big response at this time of the year. Yes Harry, it is a combi sealed system - although not as sealed as it should be given the problem we've had with it. The plumber who fitted it as I recall struggled to get it to hold pressure on test after first filling it, he said he was confident that his work was ok and that he suspected the new boiler was the problem - it is an Ariston Micro Combi. He fiddled with this and that and managed to get it to hold pressure but we had to call him back within a week or two for the same problem. It was a pattern which repeated itself a few times in the first year of the system's life and we eventually gave up on him.

He fitted TRVs but one stopped working a while back and given that it did so intermittently I'm hoping that it might be down to the sludge that has built up within the system as a result of the regular topping up via the filling loop. At the moment I have the pump and one radiator removed from the system, the pump was seized but I've managed to refurbish it but not before I bought a couple of replacements off ebay lol. I wasn't sure if the original pump would be fixable so I bid on a couple on ebay in hope that I might win one - yes, I won both.

I've actually spent a few hundred quid over the last year in putting together a bit of kit to flush the system with, it has been slow going though due to other priorities with illness and subsequent bereavement within the family. That has also been a bit of a barrier on my internet time too but I will try to get some pics up soon of what I've been buying for the job in hand to see what you think.

[HarryM1BYT]

Originally Posted by WillyHeckaslike

Ye Gods. I didn't expect such a big response at this time of the year. Yes Harry, it is a combi sealed system - although not as sealed as it should be given the problem we've had with it. The plumber who fitted it as I recall struggled to get it to hold pressure on test after first filling it, he said he was confident that his work was ok and that he suspected the new boiler was the problem - it is an Ariston Micro Combi. He fiddled with this and that and managed to get it to hold pressure but we had to call him back within a week or two for the same problem. It was a pattern which repeated itself a few times in the first year of the system's life and we eventually gave up on him.

Mine was originally installed as an open vented system, CH header tank, HW header tank and a large copper cylinder. When the original none condensing boiler was about due for replacement 6 or more years ago, I considered replacing the lot with a combi, but decided to keep what I had.



I appreciate it is more expensive to install from scratch, but it was already in and paid for. I also wasn't convinced that a combi was more economical to run than what I already had - every time you turn on an hot tap, the boiler has to fire, lots of water and heat is then wasted in run off, until the hot comes through, lots of boiler wear. The only real advantage is one of simplicity and economy if you are only in the place irregularly.



The way I run my system is - HW comes on once a day for an hour to heat a tank up in the late afternoon, to bring the HW to temperature ready for dinners washing up. There is still plenty of HW for a bath anytime after that, but it has a one hour over ride button, to top the heat up as water is drawn.



I used to have the CH set on 24/7, but found heat loss is so slow, I now get away with it being off from 23:00 to 08:00. Whilst on I adjust the CH temperature manually to suit our needs. Default is set back at 16C, which the house never gets down to except when it is really icy outdoors. We might nudge it up to 18C if we are a bit chilly, but usually don't even need to turn it up until the late afternoon. In the evening it usually gets nudged up to 19C or 20C. The stat is in the hall, which is a bit cooler than the rest of the place and has the rad with no TRV. Living room is set to achieve a slightly higher temperature on its TRV.



I paid to have someone fit the boiler, the boiler manufacturer's approved installer. He could fit it, for not much more than I could buy the boiler and fit it myself and he was happy to have me do a lot of the preparatory work for him and fit it exactly how I wanted it installed. This after various other installers tried to make a meal of the job, quoting unnecessary work, like one insisting it needed a new gas feed installed all the way round the outside of the house, from the meter, because the original pipe was too small. The pipe was adequate to feed the original 32Kw boiler, the new one just 18Kw due to the house being so well insulated since then. I don't like being spoken to as if I were an idiot

[COLVERT]

Lots of very useful information buried in this thread Willy.

Copper pipe.
1/ wire wool clean.

2/ Add flux.

3/ Make sure the pipe is pushed fully into the fitting.

4/ Don't use too much solder. (Solder comes in small rolls. Get the correct type for copper pipe. It usually has a centre core of flux. )

5/ For horizontal joints I cut a small length of solder ( 3/8 of an inch. ) and lay it, slightly bent, on the joint.

6/ Apply heat. Use a heat shield behind the joint so you don't burn your house down.

7/ When the solder reaches the correct temperature it will vanish into the joint. Keep the heat on for 1 second longer then remove it.

8/ Vertical joints are slightly more difficult as you have to gauge the amount of solder used. ( This will come with practice. )

9/ Try not to over-solder the joint as the surplus solder will end up inside the pipe.--

10/ Finally wipe of any surplus flux off the joint with a damp cloth.





( Lesson 2 tomorrow. )---