header tank overflow

brando75

hi all, I HAVE OPEN VENTED OIL HEATING SYSTEM. APPROX 25 YEARS OLD. Had pitching problem few years back where water was flowing into header tank. To combat this a plumber put a handle valve on inflow pipe to hot water cylinder. When this valve is turned about halfway water stops flowing to header tank BUT then downstairs radiators don't work properly. Turn valve off again radiators work perfect but water flows into header tank. Can anyone help with this problem?? thanks in advance

sanbrafyffe

i think you got a cowboy plumber.the only vlve that shoud be at the coil enterance to the cylinder is the bottom on which is the return to be used as a balancing valve.just to trottle down the coil getting all the heat,,if he put it on the top one god give his name to rogue traders:D

your problem is pitching

could be due to a bad design of a system

is the pump to strong and its pumping over(it could be this one)

if you can solve it why not get a decent plumber(not the last guy) and get him to convert it to a sealed system.its not hard to do

brando75

just got a new pump which i fitted last week.. problem still exists on setting number 1... when i moved first to this house 7 years back this was situation.. when heating was on all rads worked EXCEPT sitting room and hall rads which needed old pump beside fire to be on also to work. Plumber disconnected this pump and back boiler[this was heating also}.. but then this pitching problem started

sanbrafyffe

brando75 wrote: »

just got a new pump which i fitted last week.. problem still exists on setting number 1... when i moved first to this house 7 years back this was situation.. when heating was on all rads worked EXCEPT sitting room and hall rads which needed old pump beside fire to be on also to work. Plumber disconnected this pump and back boiler[this was heating also}.. but then this pitching problem started

can the feed and expansion tank be raised up to as high as it can go and the vent pipe aswell etc

brando75

not sure about this. F&E tank is on floor of attic. Also would a sealed system cause old connections to leak? If i didn't want to convert to sealed system what are my other options?

sanbrafyffe

look old connections should not leak due to converting it to a sealed system.if they are not leaking now they shouldnt then.1 bar in a sealed system is fine on the clock,,,,install an expansion vessel and change the filler point onto a mains in your hotpress

whats the problem of moving the tank up higher,you need to understand the higher the better and did you just say its a bungalow

see if it was a semi deteched 2 storey you would not have this problem

do you get it now

brando75 wrote: »

not sure about this. F&E tank is on floor of attic. Also would a sealed system cause old connections to leak? If i didn't want to convert to sealed system what are my other options?

brando75

it's a two story.. do i get what?... is installing a sealed system not hiding a design fault that will just continue causing problems??

sanbrafyffe

brando75 wrote: »

it's a two story.. do i get what?... is installing a sealed system not hiding a design fault that will just continue causing problems??

no it aint as its probably just a bad design for an open vented system thats all.once converted to sealed it should be fine and the expansion vessel can be fitted anywhere but best they say on the return side(cooler water)

you could still put your vessel in the attic like

just connect it to the mains via a filler hose check valve with a clock on it to give you the pressure inside the system.the hose also has a non return built in but remember wen you fill the system back up to reccomended pressure(1 bar is fine) to turn the black handle valve off as if left on and at nite wen the water pressure rises due to lack of use by the community it could set off the pressure valve fitted of should be fitted on the system

jimjimt

Where does the cold feed pipe enter you heating system ?

Is it near the circulating pump ?

Is it a combined cold feed and expansion ?

sanbrafyffe

sorry lad i just went back on this thread

can i ask you or i should of asked....is it a back boiler you have or an oil boiler

brando75

its an oil boiler.. old back boiler disconnected... jimjimt..i'm not sure where it enters the heating system..how would i find this out? and what is combined cold feed and expansion? sorry plumbing knowledge not great

jimjimt

If the cold feed is in the wrong place it will cause pitching.

If you look at your expansion pipe over the small tank. You will see a tee on it going into the bottom of the small tank this would be a combine cold feed and expansion.

If you see a pipe coming out of the bottom of your small tank and going elsewhere perhaps downstairs or hot press the cold feed may be in the wrong position.

sanbrafyffe

what jim is asking is,,,,is there a small half pipe going into the system near the pump especially on the negative side...if so what could happen is the pump will pull water down the cold feed and pump it back up causing pitching etc

good point i forgot to mention this earlier

however you said something bout putting a valve at the coil on th top

could it be a hole in the coil inside the cylinder.would this cause it to pitch jim.never seen this problem in any house in my plumbing days lol

i generally think thou its a bad design and the valve is put on the top coil enterence before it rises for the expansion

brando75

ok.. so expansion pipe is not teed anywhere in attic.. straight out of hotpress into attic over tank.. pipe out of bottom of expansion tank is going into hotpress where it is teed into return from cylinder and goes into floor

sanbrafyffe

brando75 wrote: »

ok.. so expansion pipe is not teed anywhere in attic.. straight out of hotpress into attic over tank.. pipe out of bottom of expansion tank is going into hotpress where it is teed into return from cylinder and goes into floor

good jasus lol.wen it goes into the floor where does that go:D:D:D:D:D

jimjimt

It would seem that this was the old gravity system for the back boiler and now used for the oil.

Is the circulating pump on the return on the oil boiler. The low pipe going into the oil boiler ?

If so it is sucking water out of the expansion tank and forcing it up the expansion.

I think a simple fix would be to combine the cold feed and expansion at the f+e tank.

brando75

not sure where it goes

brando75

yes. the pump is on the return of boiler. When you say combine cold feed and expansion.. how is this done?

jimjimt

Best get your plumber it will take about 1 - 1 1/2 hours to do.

At the expansion tank tie up ball cock. Drain down heating system to empty small tank and no more.
Cut cold feed pipe coming out of small tank.
Blank the pipe going to your cylinder.
Join from the small tank and tee into the expansion pipe slightly lower than the bottom of than your small tank.
Release ballcock make sure small tank fills between 1/4 to 1/2 up small tank and no further.
Take off valve on the expansion pipe.
All should be good.

brando75

ok jim.. i will get a plumber but i've had three up here over last 7 years and NONE have spotted what you have.. who can i trust??

does this valve have to be removed or can it just be left in off position?? it is in very awkward place. It is not placed on expansion pipe but on flow going into cylinder. So i have the flow coming out of hotpress floor coming up to a tee. This tee is then expansion pipe and flow to cylinder and thats where the valve is. On this flow about 6 inches from cylinder.

When you say blank the pipe going to cylinder which pipe is this? sorry now, but some plumbers need this explained it seems and i want to know they are doing it right.

Finally, my brother lives next door. His system is same. Feed from expansion is teed into return from cylinder. His heating works fine with no pitching? His pump is on flow from boiler. Is that the reason?

jimjimt

Best thing to do is have a chat on the phone first and ask them about the cold feed coming in behind the circulating pump.

Ask them would combining the cold feed and expansion be a cure for this.

If all is done correctly you should not need the lever valve on the expansion so remove.

If you want to do a little test first.

Open the valve on the expansion.

Plug the cold feed in the tank with a plastic bag or bung of some kind that will not get suck in by the pump. Even if you do not use a bung you should feel the water being suck in by the pump inside the tank down at the outlet fitting with the heating is on.

Turn on the heating and see what happens.

Dont forget to remove the bag/bung with you are finish.

sanbrafyffe

if your in kilkenny city i know a lad that will sort that

brando75 wrote: »

ok jim.. i will get a plumber but i've had three up here over last 7 years and NONE have spotted what you have.. who can i trust??

does this valve have to be removed or can it just be left in off position?? it is in very awkward place. It is not placed on expansion pipe but on flow going into cylinder. So i have the flow coming out of hotpress floor coming up to a tee. This tee is then expansion pipe and flow to cylinder and thats where the valve is. On this flow about 6 inches from cylinder.

When you say blank the pipe going to cylinder which pipe is this? sorry now, but some plumbers need this explained it seems and i want to know they are doing it right.

Finally, my brother lives next door. His system is same. Feed from expansion is teed into return from cylinder. His heating works fine with no pitching? His pump is on flow from boiler. Is that the reason?

brando75

no, i'm not in kilkenny. north kildare-dublin border.. leixlip.. Yes Jim. I just did your test. So as suggested I CAN FEEL WATER BEING SUCKED FROM EXPANSION AND WHEN I BLOCK THIS PIPE WITH FINGER THE PITCHING STOPS. when i combine feed and expansion can this cause any other problems down line.. as i said before old back boiler and old pump at fireplace all now disconnected

jimjimt

The best place for the cold feed when the pump is on the return is in front of the pump. But most likely not possible in your case.

Some will argue that a combined cold feed an expansion is not proper. I personally never had a problem with it ever.

At least now you know what the problem is.

If your brothers house is the exact same plumbing set up in every way. Changing the pump to the flow may solve it. You would also have to look in his attic and f+e tank.

brando75

i will talk to couple of plumbers and see what they have to say. thanks for identifying problem.

i need a rad replaced also so i will drain down all system to do all work together. Just wondering when i have it drained down should i put balancing valve on return from cylinder. i want to be able to heat water in summer without necessarily heating rads. Is this what balancing valve is for?

jimjimt

Do put a balancing valve on the return on the cylinder. It will not turn of the rads. It will balance the flow of water going to the radiators and cylinder when all are on together.

To turn of all your radiators you will need a lever valve on either the flow or return circuit going to your radiators. If you have a two story you may be able to put two lever valves on one for down stairs and one for upstairs. Or if you want to splash out you can get electric zone valves. Or a full house zoning kit with time clocks, room stats, cylinder stats saves on oil and trv's for your radiators.

brando75

jimjimt wrote: »

Best get your plumber it will take about 1 - 1 1/2 hours to do.

At the expansion tank tie up ball cock. Drain down heating system to empty small tank and no more.
Cut cold feed pipe coming out of small tank.
Blank the pipe going to your cylinder.
Join from the small tank and tee into the expansion pipe slightly lower than the bottom of than your small tank.
Release ballcock make sure small tank fills between 1/4 to 1/2 up small tank and no further.
Take off valve on the expansion pipe.
All should be good.

Jim, on this post you say BLANK THE PIPE GOING TO YOUR CYLINDER. which pipe is this?? is it the cold feed which is teed to return of cylinder??

jimjimt

Yes this would be the cold feed pipe going to the tee at the cylinder.

If you are getting a plumber back to do some work, you know what the problem is now and you can show him, he should be able to deal with it.

brando75

great jim. thanks for all advice. much appreciated

brando75

ok..talked to one plumber today who came in and suggested changing system to sealed one.. said the idea of combining feed and expansion WOULD stop the pitching but expansion would not serve as an expansion anymore as it would now be a feed.. He said it is improper pipework and a sealed system is a BETTER system than an open vent system.. any thoughts?

shane0007

brando75 wrote: »

ok..talked to one plumber today who came in and suggested changing system to sealed one.. said the idea of combining feed and expansion WOULD stop the pitching but expansion would not serve as an expansion anymore as it would now be a feed.. He said it is improper pipework and a sealed system is a BETTER system than an open vent system.. any thoughts?

I would agree with your plumber. A combined feed & expansion is only a fix of the symptom & not of the cause. It is also a poor design as water can only travel in one direction through one pipe at any given time. It will either be a feed or a vent & the feed normally wins out so you have no open safety vent!
It is also a buggar for air locking as when it is being filled, the air cannot pass out the vent being blocked by the water filling the system.
If you cannot easily solve the issue and it is probably to do with the location of the vent, i.e. in front of the pump (pump over), then a good solution is indeed to pressurise your system. This is indeed a better system but it could potentially highlight other issues, such as leaks or weeps. Better IMO to know about them rather than a f & e tank hiding it though.

jimjimt

Just out of curiosity did your new plumber identify the cold feed in the wrong place or did you have to tell him ?

A sealed system is a better system but you have to consider your heating system is 25+ years old. It will put your pipe work and radiators to the test. So be prepare for a larger budget if your system cannot handle being pressurized and this should be explain to you before work commences.

You have a couple of more options.

Combine the cold feed and expansion. They are also pro companies who have design special fittings and devices for this option. Aerjec de-aerator is one option and their is more.

Also note the expansion pipe is coming of your cylinder and not from the oil boiler so technically not a true expansion for your appliance.

Move the circulating pump to the hot press and move the cold feed in front of it. If you can get a wire to the oil boiler and you can pick up the radiator circuit in the hot press. Most likely not but maybe.

A semi pressurized system.
As in use your small tank to feed your heating system. At the cylinder where the cold feed is teed in put a non return valve on the cold feed. Blank the expansion. Put an expansion vessel on the oil boiler. A lot more forgiving than a full blown pressurized system.

Always more options.

brando75

Firstly jim, that test where i opened valve on expansion then plugged feed in expansion for a few seconds and this stopped the pitching.. i done this with my finger couple of times. I then closed valve off again and since heating is working great downstairs. Whereas before with valve closed downstairs was only working at about 30-40%. Would this suggest there was an airlock or blockage that's now released??

ok, so plumber said even with this cold feed teed to return it should still not be pitching. That more than likely there is another design fault somewhere.He said to seal system but i am little worried about these old connections and fittings so he has suggested semi sealing system which is still fed from expansion tank. With this system can expansion vessel be placed in attic or MUST it be placed on oil boiler like you have suggested.

thanks again for all advice

mloc123

Having the same issue myself at the moment. Water is pumping over into the f&e if I turn the pump above the lowest speed, with the pump on the lowest speed the radiators downstairs do not heat very well.

My expansion pipe could be made 6 inches higher, I am not sure if that will be enough. I am interested in the combined pipe setup. Am I right in thinking the below before and after is correct?

jimjimt

Most likely their was a bit of air there trying to escape.

If the cold feed is behind the pump on the return it sucks. That is the design fault and you proved it yourself yesterday.
The cold feed most be in front of the pump if the pump is on the return. Plumbing basics.

All boilers like to have the expansion vessel close to the boiler. So it would be better beside the boiler.
You will need an air vent in the hot press on the top pipe flow pipe on the cylinder.
A semi pressurized system will suit you best as it is a lot more forgiving than a full blown pressurized system.

Dtp79

mloc123 wrote: »

Having the same issue myself at the moment. Water is pumping over into the f&e if I turn the pump above the lowest speed, with the pump on the lowest speed the radiators downstairs do not heat very well.

My expansion pipe could be made 6 inches higher, I am not sure if that will be enough. I am interested in the combined pipe setup. Am I right in thinking the below before and after is correct?

Where is your pump located ? The first drawing looks wrong, basically the small tank in attic will work like a rad. The second drawing isn't totally right either but it should stop the problem occurring

jimjimt

You would have to mark in where the pump is on the drawings and what direction it is pumping.

I would presume red is the flow and blue the return. Which would indicate that the return is piped to the top of the boiler ?
Which I presume is not the case in reality ?

mloc123

Better diagram now.

So, I presume because the the cold feed is behind the the pump it will always pitch no matter how high the expansion pipe is?

It does not pitch with the pump on its lowest setting but the downstairs radiators do not heat fully. My main options are.. move the feed in front of the pump or T it into the expansion pipe?

jimjimt

Move the cold feed in front of the pump would be the proper way to do it.
But sometimes it is not possible.

I have combined cold feeds and expansions in the past with out any issues.

If you can get the expansion pipe up higher do so. This is always good.

The reason it is not pitching at a low setting as such the pump is at the end of its curve and cannot physically pump over the expansion or suck in from the cold feed.

So if the pump was at setting 3 and your expansion was up high enough it could not pitch. Probably about 8m above the pump i would guess maybe a little more.

So a 5 meter circulating pump can pump to 5 metres in height with very reduced flow rate.

Have a look at a wilo pump curve below,

Dtp79

mloc123 wrote: »

Better diagram now.

So, I presume because the the cold feed is behind the the pump it will always pitch no matter how high the expansion pipe is?

It does not pitch with the pump on its lowest setting but the downstairs radiators do not heat fully. My main options are.. move the feed in front of the pump or T it into the expansion pipe?

Yes either will do. At the moment your small tank in the attic is a radiator. You could also seal the system if there is no solid fuel boiler on the system

brando75

jimjimt wrote: »

Most likely their was a bit of air there trying to escape.

If the cold feed is behind the pump on the return it sucks. That is the design fault and you proved it yourself yesterday.
The cold feed most be in front of the pump if the pump is on the return. Plumbing basics.

All boilers like to have the expansion vessel close to the boiler. So it would be better beside the boiler.
You will need an air vent in the hot press on the top pipe flow pipe on the cylinder.
A semi pressurized system will suit you best as it is a lot more forgiving than a full blown pressurized system.

I'm at this stage opting towards a semi sealed system. The plumber seemed to be talking about putting expansion vessel in attic. Are you suggesting a better place is beside boiler outside in small shed?? If so is this a much more complicated/expensive way to semi seal? or is it more or less same job.

Something else about my current system i'd like to mention. When i moved in 7 years back this was the set up. For some reason my flow and return are piped into kitchen, then go straight upstairs across back bedroom floor and are teed into flow and return near to hotpress under floor. That's the flow and return from cylinder to old back boiler. Is this normal? Would it be causing any problems with efficiency? Will it cause any problems when sealing system? What way should it be piped? Would it be major job? thanks again for all replies

jimjimt

brando75 wrote: »

I'm at this stage opting towards a semi sealed system. The plumber seemed to be talking about putting expansion vessel in attic. Are you suggesting a better place is beside boiler outside in small shed?? If so is this a much more complicated/expensive way to semi seal? or is it more or less same job.

Something else about my current system i'd like to mention. When i moved in 7 years back this was the set up. For some reason my flow and return are piped into kitchen, then go straight upstairs across back bedroom floor and are teed into flow and return near to hotpress under floor. That's the flow and return from cylinder to old back boiler. Is this normal? Would it be causing any problems with efficiency? Will it cause any problems when sealing system? What way should it be piped? Would it be major job? thanks again for all replies

All boilers like the expansion vessel at the boiler. Gives the boiler a better life span. No big job, tee, valve,and pipe to vessel, job done. If for no other reason your vessel will have to be checked every year to insure it is working ok. It will be forgotten in the attic.
The slow death of all gas and oil boilers is a uncharged pressure vessel.
So when you get your boiler service you can get your vessel checked as part of the service.

It would be better for your pipe work to be more direct. Unless you are doing a major renovate in your house probably not reality.

So are all rads working ok, head to toe and in the middle ?
A larger circulating pump can work wonders to give your rads a boost along with a good power flush and clean.

brando75

All rads working except sitting room which is last on system. This rad however does work when i open valve in hotpress so i'm hoping when system is semi sealed and valve is left open this rad will heat. Probably needs balancing also.

Where should these pipes be joining system. Should they come in at ground level and join in at fireplace where old back boiler pump was? I know exactly where they are teed in from previous renovation.. just a matter of small hole in sitting room ceiling and disconnecting. But if i brought in two new pipes from boiler where could i join them in?

jimjimt

brando75 wrote: »

All rads working except sitting room which is last on system. This rad however does work when i open valve in hotpress so i'm hoping when system is semi sealed and valve is left open this rad will heat. Probably needs balancing also.

Where should these pipes be joining system. Should they come in at ground level and join in at fireplace where old back boiler pump was? I know exactly where they are teed in from previous renovation.. just a matter of small hole in sitting room ceiling and disconnecting. But if i brought in two new pipes from boiler where could i join them in?

Hard to say this is where you need an experience plumber to survey and advise.
Pipes in general would be better at a more direct route that going up and down. But their maybe a reason they were done like so.
This is where one would have to see.

mloc123

So I raised the vent pipe the 6 inches I had to spare and it reduced the pitching to a drip.

Dropped the tank level 2 inches and it did the trick. What are my best options for dropping the water level? Is bending the ball cock arm really the best option?

jimjimt

mloc123 wrote: »

So I raised the vent pipe the 6 inches I had to spare and it reduced the pitching to a drip.

Dropped the tank level 2 inches and it did the trick. What are my best options for dropping the water level? Is bending the ball cock arm really the best option?

Bending the ball cock is how all the pro's do it.

Pitching may restart at high temperatures due to water expansion. Have a quick look / check once or twice to insure it is or not.

mloc123

jimjimt wrote: »

Pitching may restart at high temperatures due to water expansion. Have a quick look / check once or twice to insure it is or not.

That was one of my concerns left the heating on for 2hrs and checked, all good.

Threw some sentinel x400 in while I was at it so I will flush out the system fully in a week or so and bend the ball cock.

Dtp79

mloc123 wrote: »

That was one of my concerns left the heating on for 2hrs and checked, all good.

Threw some sentinel x400 in while I was at it so I will flush out the system fully in a week or so and bend the ball cock.

When u say "flush" the system I'm assuming your talking about a proper 1 day job and not talking about draining the x400 and refilling the system??

jimjimt

Pouring sentinel into the tank is not much good unless you drain some water first. As it has no where to go.

Dtp79

jimjimt wrote: »

Pouring sentinel into the tank is not much good unless you drain some water first. As it has no where to go.

He might as well pour it into the toilet if he's not gonna flush the system properly!!

mloc123

I had drained the water down enough to get it into the system.

When I said flush, yeah drain the system down... Fill, drain.. repeat a couple of times. I presume the flush you are talking about is some forced system?