Is Your Central Heating System Losing Pressure? 

Great to hear!

Glad it helped

Did you manage to get it fixed or a new one? Am having the same issue now with mine 🤔

I hate putting drain cocks under floors. I usually stick them outside.

@@SkillBuilder it was an inherited system of course. Still looking for the Magnaclean. Theres a spanner for it but no sign of any filter! Got a Fernox TF1 Omega to go in, much better filter anyway, size and ease of service.

Wonderful!

Chris Crawley bloody towels

there *were

Hi David It is very easy to top up the expansion vessel. You need to drain a bit of water out of the system so the needle is on zero. Pumping up the expansion vessel is the same as pumping up a bike tyre. You are looking for just over 1 bar. If there is spare capacity in the system the expansion vessel will not have to work against a dead head of water. You only need to drain a bucket full out of the system. When the expansion vessel is topped up you simply repressure the system from the filling loop.

@@SkillBuilder Many thanks for the information, that's very good of you.

Glad it was helpful!

Great to hear!

​@@SkillBuilder so if the blow off is spitting out water .. & the existing vessel in the boiler is gone .. can an expansion be cut in on a line elsewhere an leave the old one in place ?

@@wittywoo9559 and* leave

Gixer750pilot it comes pre charged

It should be topped up to roughly 1 bar with the system at zero. The idea is for the membrane to expand fully and when the system is filled with water it presses against the membrane. If the cold pressure in the system is the same as the pressure vessel as it heats the expanded water pushes against the membrane and creates space for the water.

yes I think we can do that

I feel for you. An innocent repair and you are there all day sorting out existing problems and nobody wants to pay you for that.

Derek Stocker could be cracked heat exchanger or nitrogen forming in rads then escaping through the auto air vent.

@@burntre1 Hello there, thank you so much, this is another thing I will get my heating engineer to look at, that I would never have guessed at, absolutely maddening with no obvious leaks!

You do know that plumbers charge for time spent scratching thier heads.......

@@flipper2392 Oh yes, seen plenty of that BUT, got a decent REAL plumber at last, immediately did a thermal image job (that one had done and charged a load JUST for the looking so was not going to risk more on the job fix with him) found an under tile floor leak through an old pipe joint. Fixed and done in two days for just a little more than the guy with the thermal image camera charged, EXTREMELY pleased and did not need a whole new system as one "expert" told me! 2nd or 3rd opinion vital in my experience.

faulty gauge ? ...

Either the Pressure Relief Valve has failed to reseat and you have a weep from the PRV termination, can be ruled out with a party balloon attached with a rubber band over the termination; or the heat exchanger has a crack, and you're losing water inside the combustion chamber on a standard efficiency boiler or down the condensate pipework on a condensing boiler. Probably do with a better engineer to be honest; if the system has been eliminated from the equation, it can only be the boiler, and domestic boilers don't have many places water can escape from or to.

Thank you Mike, great info to have when the Manufacturers Engineer comes out.

There's a good chance your boiler may have a leak within the heat exchanger or from the prv as mike suggests. You don't say what system your on. Do have a pressurised system/conventional boiler which a hot water cylinder? If so you may also have a pin hole in the coil causing heating water to leak into your hot water system. Other things to consider is what sort of floors do you have? Wooden/floating floors won't show up leaks as easy as screeds. I've also had it in the past where a system would only leak when the heating was on, through the summer you would get nothing but in the winter when the heating is on, the pipes get nice and hot and when they expand the leak shows itself, this can be a common issue if compression fitting are buried in the floor. If you have have no look with the manufacturer on Monday then look at hiring a thermal imaging camera, wait for your heating to get hot and using the camera you'll be able to trace where all your heating pipes run, you should just see distinctive orange tubes but if you see a pool of orange then that would indicate a leak. Good luck

Thank you Craig it’s a grant vortex, oil boiler similar to a sealed combi. We are in a bungalow with the pipe work going up into the loft and then it comes down the walls. I will a try the thermal Imaging camera on the walls and ceiling . I do remember the auto blead valve being changed a few years ago, that is definitely a area to look at. Thanks again I now have a much better insight into were to look. Hope fully the engineer will appreciate it !

It is the oxygen in the water that causes rust. Once the water has been run around for a year or so it loses its free oxgen and the result is black rust magnetite.

no they need to be open but you can turn the heating off

I think you just need to screw in a new pressure guage, It happens every so often, They are cheap.

Hi bud mine is on 1qurter, when I put heating on it goes 2,, 2 bar is that normal?

Hi Paul Leave the expansion vessel in the system it will do no harm at all and could do some good. A lot of combis have limited expansion capacity and with underfloor heating and large systems an extra vessel is standard procedure

@@SkillBuilder Cheers kind sir, thanks so much for the advice, much appreciated. Keep up the great videos

Hit and miss. I don't trust them but they help

You need to pump the expansion vessel up with a car pump so it is equal to the static pressure. Release the water pressure from the system so it is below zero, then pump the vessel up to 1 to 1.5 bar then put the water back to 1.5 bar cold pressure.

@@SkillBuilder What is the static pressure? When you say release water pressure do you mean I need to empty the water tank? also what does '1.5 bar cold pressure.' mean exactly? Sorry for all the questions!

Hi Malcolm What did British Gas say the problem was (is)?

@@SkillBuilder they all said they couldn't find a fault, they all used a foot pump and said the water coming out the overflow was normal even though we told them it's just started more often, when the water wont heat there is a water icon on the screen next to the temp that blinks , this stays on permanently when ok,hope this helps and thanks for getting back to me mate

Where do you live?

@@SkillBuilder Palmers Green, London

That seems a good deal. I have paid £90.00 for one in the past.

What’s holding that expansion vessel up? Just the pipe work??? Lol! What happens when the diaphragm inside goes? It’ll end up flooding the place. Quarter of a bar will only reach 2.5 meters above the gauge.

@@jimmyman8031 there will be a bracket behind the vessel which clamps onto that grey rim round the middle of the vessel. And when the diaphragm fails you no longer have an allowance for expansion, when heated up your water will continue to expand raising the pressure above 3bar causing the prv to activate. Then you will continue to suffer from pressure loss until your expansion vessel has being replaced and in most cases the prv too.

I didn’t know they did brackets for a 35 litre expansion vessel. That’s why they’ve got feet. Where can I get these brackets from that you mention? As any bracket up to 25 litres you mention is too small to fit over that rim.

@@jimmyman8031 or maybe it's got feet to give you the option for either wall or floor mounting. I'll also point out that you are only assuming it's a 35 litre, could easily be a 24 litre as the size difference between the two are fairly similar. Not to point out the obvious but if the vessel wasn't fixed to the wall how do you think it's held there? This isn't a new installation, and when the system is full that vessel will weigh between 20 and 30kg so it wouldnt stay fixed to that pipe for long if wasn't held to the wall by one of those imaginary brackets you claim don't exist.

It will settle down. There is a pressure relief valve which might let out the excess or you could bleed a radiator into a cup.

The water regs say you can't leave a permanent connection between mains and heating system but a temporary filling loop with a non return valve is allowed. They just say it must be disconnected after topping up the pressure.

Me too. Wonder if the expansion vessel needs a recharge?

@@colinbaines6703 my plumber says I've got a leak on the system, but to find it I'd have to rip up the flooring andvthe downstairs is laminated,; or we might even have to chizzle out wall. it's easier to keep topping it up.

I've checked everything I can see. It runs fine all day and loses pressure when it goes off. I'm going to check the expansion vessel next as its 14yrs old. Hope you get sorted. It'll be a nightmare to find for the both of us!

I bought something called Fennox F4 leak sealer when the plumber comes to service my boiler next month I'm going to ask him to put it into the system and see if that works might be cheaper than ripping the house apart.

It could be a leak through your plate heat exchanger. Turn off the mains cold water supply into the combi and lower the pressure in the heating system then see if it rises. If it doesn't turn on the cold water mains into the boiler and see what happens. If the heat exchanger is leaking it is a simple swap over.

A bracket that dimbo`s like you cant see : )

OK @@paulp1008 Look at the vessel again its not mounted like it should be hence the feet on the bottom . DIMBO

yes but in this instalation the feet are redundant..hence the silver strap around the middle attached to a wall bracket...dimbooo : )

How do you think flamco wanted that hung on the wall DUMBO @@paulp1008

with a wall bracket DUMBO..

Leave it there. It is not doing any harm.

@@SkillBuilder fantastic thanks Roger

The pressure vessel needs to be recharged with a pump every so often. It does not mean it is broken. You need to drain some water out of the system so the pressure guage is at zero then charge the pressure vessel to the cold pressure of your system which is 1 to 1.5 bar. Then top up the system to the same pressure cold. You will then see the pressure gauge rise slightly when the heating warms up.

Skill Builder thanks 👍

I thought that because it looks like it is hanging on that 22mm pipe but when I looked closer it has a big bracket on the back. The legs are an alternative mounting option

a sliding bevel is a philips screwy aswell...

Where I come from, a butter knife is classed a screwdriver. So wind your neck in Rob.

Im only joking, I have a few rolson tools knocking around. A cheap flathead screwdriver is a must to be honest as you can bash it about and not worry.@@williammcgrattan9583

I do that sometimes as well. Just open it up enough

Would you like to do a Zoom call on this? I could look around