A very puzzling problem with Heating System.

[Riverside]

Hi All,
I have a bit of a plumbing puzzle you might be able to help me figure out; the attached drawing is the system in my in laws home. I can send an attached drawing of the system in my in laws home to anyone who might be able to help.

They used to have a separate hot water tank in the attic but it was replaced by a plumber a few years ago with the current system, it has me driven mad.

I replaced a rad for them, and shut off the water to the system as my step father said he normally would, I drained the system at the boiler as he said he normally would.

When the water had stopped, I removed the rad, it was the last rad down stairs on the system and I just capped the pipes close together rather than rip up the floor all the way back to the next rad and then the second thing I did was I fitted a new double rad farther back the system in the same spot as an older single one.

The old plumber had disconnected their back boiler a few years back but rather than remove the built in furniture and concrete floor and cap the pipes the lazy bugger stuck some plastic pipe into the line to make a loop, at the same time he took out their hot water tank in the attic and place in a expansion vessel (CIMM 18 ltr EXE CE).

I also found a leak on a buried pipe so I fixed that and left all the new fittings exposed for the weekend to make sure leak free. My father in law said that the system refills itself after a while so I thought it must be an automatic top up sealed system, no worries says I. The rad's all heated and hot water came from taps and the rad’s bleed so off I went.

The leak I had discovered didn’t seal up fully so back I went after 2 day and did a job on it, I drained the system again and a bit of swearing and grunting later I stopped the leak fully and filled in the pipe channels in the floor with sand and sealed the floor with screed.

Then the doubt started. Where was this auto top up valve located?, I went back for another look as the hot water line had air locked on them and after freeing up the lock and restoring water I traced the whole system that I could find, now I am completely freaking out as I cant for the life of me understand where the hell new water is getting into a system that I have drained twice in the last week, I really want to add some inhibitor and get around to balancing the rad’s fully, but I am completely lost now and tearing my hair out.

SO long winded post but questions for you all please?

1. What type of system am I looking at?
2. Where is the top up valve?
3. Am I after capping a pipe I shouldn’t have?
4. If I had made a mess of it how in god’s name does the heating still work?
5. Why did I ever agree to do this job for them?

I'm after answering the question after a bit off thinking and some good advice about items that may not be on the system if the plumber just threw stuff together without bothering to really fix the system when he replaced the hot water tank inthe attic with a sealed system.

He connected the auto fill valve way up in the attic to the old back boiler return line, this made the back boiler loop that I just blanked fairly important, he also left a stray 3/4" line that is trickle feeding the system some how.

I'm going to track down my stray lines and repair the system.

I'll add a proper filling loop, pressure gauge and relief valve into the heating line in the in-laws boiler room its really big loads of space and had mains water running through it.

Why the plumber didnt do it in the first place I dont know lazy bugger I guess.

Sorry so sticking up such a long post, but thanks to anyone who read it.

 

[Rodreguez]

ive never seen a system with an autofill valve. thought a filling loop was only way to fill a sealed system(apart from a pressurisation unit but these are more often in commercial installs). Is this autofill valve basically a pressure reducing/regulating valve set to 1 bar? And would that also contravene the water regs? As a filling loop should always be left disconnected!

If that is the case it might well be he done this because he knew there was a leak and didn't wanna fix it.

 

[Riverside]

Hi Rod,

The lad who fitted this was as much a plumber as I am a astronaut. He knew how to charge mind you. king robber.

Thats all an auto filling valve is really, Its a small non return valve with a pressure gauge attached inserted into the mains feed line to add water into the system up to one bar of pressure and keep it there topping up constantly. Ireland still has not caught up to the UK regs as we are often lagging behind in regulations.

You should see the state of the job this guy did, any where he could cut a corner he did, loads of pipes without insulation, pipes kinked instead of bent.

He didnt size the main big room rads correctly, he had a single rad of 4000 BTU where double rad of 12200 BTU was needed, this was the main sitting room where one wall in more or less all window.

And this home has so much space available to fit pipes, valves etc. he could have done a lovely job but they pegged any old thing in there.

 

[WHPES]

Are you sure there are no more parts to the decommissioned back boiler system you haven't found yet? They often came with a circulation pump and bypass valves here and there.

Alternatively have you checked the condition of the coil in the cylinder? If it is rotten then it may be passing water from the DHW side. Easy way to check when the system is drained - crack open the bottom connection of the coil and see if it drips.

 

[Riverside]

Hi WHPES,

The guy remove everything in the wall and just added a loop of plastic pipe behind the plaster board in the space where the boiler used to be.

The dual coil cly he fitted seems to be good quality so i do hope its not the coil when i investigate the where my mystery 3/4" line goes after it tees off from the auto fill line I should have every pipe in the system tracked down.

I have a disconnect 3/4" black waven pipe in the attic just lying around and heading off somewhere that I really want to know where that goes as well so I'll have no surprise there.

I love working on systems that have snakes weddings for pipelines and a good who dunnit as well.

Oh by the way is it good practice to support underfloor pipes in there channels with sand and then seal the floor with screed (I might be late asking that question if you catch my drift)

I am doing this job for free qratis by the way so any free advice will be past on.

 

[Mbear]

If u can't find a fill valve anywhere just fit a new one.

I'd put it beside expansion vessel if there's a mains pipe nearby. Also fit a pressure gauge if there's not one there already. Has the this plumber fitted a pressure relief valve&pipe?

Apologies, ignore my post, I didn't realise it was an oil boiler

 

[Riverside]

Thanks for the reply guys.

I think I'll do the following as per the drawing below.

I'm going to remove and or cap off all the old auto filling lines and any stray line I find.

I'm going to fit a flex filling loop of mains supply on the return line to the oil fired boiler.

I'm going to tee a line into the flow out of the boiler and add a pressure gauge and pressure relief vavle side by side.

So you will be able to see the gauge while filling the system. this will all be located in the boiler room it's a grand size so loads of space for working.

The pump on this system is on the return line from the system, should I swap it onto the flow out of the boiler or leave it alone?

The flow comes out of the boiler onto the main rad line under floor into first rads and on into the hot press on the ground floor and goes to the top of one side of the dual clyinder, this line is tee'd off and goes up into the expansion vessel in the attic over the 2nd story.

Should I move the expansion vessel out into the boiler room and place it on the return line as well?

Figured out where all the pipes were going.

The mystery 3/4" line was tee'd into the auto fill and the expansion line as per the red line on the drawing below



I'm going to remove the auto filling system and refit everything in the boiler room like the drawing below



The main return is about an inch of the ground and only has a foot of run to the pump and another foot to the bottom of the boiler.

I will if I can:

1. Stick in an extension of pipe running out in a loop and then into the boiler.
2. Tee'd of that line wil be my bits and bobs.
3. The Exe Vessel will be wall mounted about a two feet of the ground to give me lots of nice open space and easy installation. This is fine if I have the vessel mounted opening up and the pipe coming off and going down.
4. Should I attach the filling loop before or after the vessel?, I'm thinking before.
5. I will have to tee the magnaclean in upright so I'll have an interest arrangement of pipes, along the floor changing to upright, into magaclean, outta magnaclean, and back down to the floor into the resited pump.

I have a vertical return pipe from the hot water circuit dropping down the wall and teeing into the RAD line before the old pump, the magnaclean filter wouldnt work as well there I take it because the full flow of the system isnt passing through it all the time.

But would my completcated arrangement of pipes create to many bends before a pump and incress my chances of wear here?

 

[Riverside]

Just quick word to say thanks to anyone who helped.

Found lots of intereting kinks in the system that are now gone and the heating is working a charm.

In the end i went for a very simple arrangement of pipes as possible I couldnt put the filter in the ideal place on the feed to the rads, but I put it in the second best as recommended by the maker just before the rads main line.

Airlocked the main cly coils which were a nightmare to get out but a slowly and steady cleared the air out.

the system works a treat now, charges really fast and is simply to operate with no climbing into the attic involved. The system pressure is holding steady at 1 bar while cold so I have no majorleaks anywhere but I'll keep and eye on it.
I have to clean and inhibit the system and I'm going to leakseal as well over the next few weeks.

just a note on the maganaclean professional filter I fitted, comes with ok instructions and all the bits you need and is supllied with chromed fittings to join your central heating pipes, BUT....the body of the filter is plastic and the threads are VERY EASY to crossthread, anyone fitting it should take great care to fit the shutoff valves to the body and then to the pipes, the filter costs at least 100 euro and the thread are plastic very poor design IMHO.

 

[JamesC]

Another thing mate, is the back boiler decommisioned correctly?
If not needs to be.

 

[Riverside]

thanks for asking jamesc, the old plumber didnt do a good job and when they went to use their fire for the first time after he had left the in-laws got massive billows of smoke coming out everywhere, they had another guy come and he sorted it out, they have just replaced the whole fireplace and while it coming out the back boiler was removed fully by the fireplace fitters.

so hopefully they will have no more problems with their heating.

It a shame that good people can be taken advantage of by someone who was recommended by a friend. He was some cowboy.

Think about this, I had ordered 12ft of 3/4" copper and 12ft of 1/2" to make the new pipe runs etc., so i would have enough to hand to make good anything I encountered, but I pulled so much unused cut off's lengths of 3/4" from the attic and so much waste 1/2" pipe from the systems in the wall that I cancelled the order in the end I only used about 8ft of 1/2" and 5ft of 3/4" all of it the recycled stuff, my local hardware store was fine with cancelling the order thankfully,