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.