woodburning stove problem

[pioner]

Hi sambotc
I have gone round the rads, to balance them myself, and I did not find it made much difference, I also knew which is the flow and return, as I fixed them in the first place, many years ago, and I had also marked them for the heating engineer, to save him time checking them out.
I have also tried turning the rads off in the lounge, and the others got warmer,in other rooms, BUT, it went a lot cooler in the lounge, even with the stove on, you see, when I put the gas boiler on, all the rads get warm and in about half to thee quarters of an hour, all the bungalow gets comfortable,and that is only on the second setting I have had it on the third setting and it really gets warm, for me anyway,
if the stove got the rads as hot as the gas boiler, I would be a happy man.
I will try turning down the pump speed in the morning and light the stove
to test your theory out.and will let you know.

pioner

 

[pioner]

Hi sambotc,
This morning I was in the attic before 8-o clock, the gas heating had been on from six am, so I turned it off, leaving all the pipes still warm I turned on the stove heating pump to see if it was running, then I turned it down to No two, as you suggested, I also double checked that the pipes where connected to the right ones, ( IE flow and return ) they where OK, so I lit the stove, with logs, when they had burned down (which does not take very long in my stove as it is very greedy) I then loaded it with anthracite, it really was a fierce fire, but on checking the pipes going up to the ceiling from the stove I found the 28mm pipes ( gravity ) going up to my cylinder, got hotter quicker than the 22mm pipes for the heating, BUT, within an hour, all my radiators got really hotter than I have ever known them to get, I turned off the three rads; in the lounge, and the others got hotter still, I could not keep my hand on some of them, which have never got much higher than coolish, so my deduction on this, is that I would like to harness some of the wasted heat from the gravity side, and get it to the heating side, where I would give it 45% at first,
I would now say, with your very valuable advice, it is at least 75%, but if I could get the wasted heat into the heating side I think I would give it 90/95% and I would be a very happy man, and to be honest, at first I was beginning to think that I had wasted my money, but, many thanks to you I think you may have solved my problem, What is the best way to transfer this heat,

Many Thanks
pioner

 

[sambotc]

Hi pioner,

Glad to hear we are on the right track.

Firstly, the 28mm gravity circ's to the cylinder will always have priority due to there size and free flowing design.Also they circulate at just the right speed!

One option is to add a motorised valve/cylinder stat to the 28mm return just after the cylinder connection. To do this you will have to fit a normally open valve. This means that in the event of a power cut, the valve will return to the open position to safely dissipate the heat your stove will still be creating.

Alternatively it may be possible to remove the cylinder connection all together, but to do this safely I would say the heat leak rad would have to be increased in size dramatically.

If you take a look in my photo's there is a diagram showing a similar set up to yours and how it can be possible to use the heat leak radiator in a room downstairs. The only problem would be return pipework and how it could be routed.

You can try and run the system on pump speed 1 if you like to see if it helps.

It is simply a case of balancing the heat to gravity vs heat through pumped system, but ensuring that the stove will not boil over when the pump isn't running. Adding a 28mm gate valve on the cylinder return could be another option to reduce flow slightly, or throttling down the heat leak radiator valves slightly.

It seems you have some plumbing skills so you should be capable of some fine tuning

HTH Sam

 

[pioner]

Hi sambotc,
Thank you for your responce Sam,
But What do I do to look at your pictures?
I seem to only be able to get my own pictures.
Cheers
pioner

 

[sambotc]

Untitled

• sambotc
• 8 Aug 2008
• 4

How's that?

If you click on the image you will get a larger version pop up.

HTH Sam

 

[pioner]

sambotc
Sam, Thank you for YOUR picture, I have just taken a picture, of a live radiator,in my rear lounge which has tee's from below the valves going through the wall to feed another radiator in my front lounge, I could put elbow's on the flow and return to kill the radiator in the picture, leaving this to act as the gravity radiator.
In the picture you can also see the pipes going up to the ceiling, would I be OK to connect at that point,on the elbows with the flow and the return, to this radiator using it as the gravity radiator? and take the boxing down to a lower level

cheers pioner

 

[sambotc]

I think I understand what you mean. split the 2 radiators which are 'back to back' and share the same feeding pipework. Then connect the rad in the picture to the 28mm flow and return in the boxing?

If thats the case then I doubt it work. The flow to this radiator needs to come from the highest point on the system (ie where the 28mm flow connect's to the cylinder) Ideally the return should carry on along the skirting board height and join the return to the boiler as low as possible. Having a rise in the pipework on the return may reduce it's efficency to circulate, especially considering the majority of heat loss will take place low down (radiator position)

Connecting intot he return higher up to where the pipes are in your photo may work though.

22mm pipework to within 300mm of the rad valve is recommended, although i've seen it in 15mm many times, and there have been no problems.

The valves on this radiator must be lockshields so that it cannot be turned off, not thermostatic valve.

While your at it, check the F&E tank and ball valve/float is rated up to 110oC. Ideally the float should be copper.

Sam

 

[pioner]

Hi sambotc
I could get the flow down in the front lounge in the corner with a plastic duct, But the return, I may as well say, without having a rise is impossible, as I would have to go through the chimney breast to do that, and then it would be impossible to connect anything without taking the stove out, ( as there is no room ) but I can see the reason why there has not to be any rise.
I thought we had solved it. but we are back to square one.

pioner

 

[sambotc]

Only to take advantage of the heat leak. Try reducing the pump speed to 1. If that doesn't work, add a 28mm gate valve to the cylinder return. Use this to slowly throttle the flow down.

Thinking about it you said the installer switched the pump off and it boiled? If so then this would indicate the heat leak is not big enough, depending on the severity of the boiling.

You could connect the radiator in the lounge as we discusssed but leave the existing heatleak in situ, and connect the return to the 28mm return as you described. You certainly won't be doing any harm. If you then find it circulates well, you could gradually close the heat leak in the loft down.

It's all about balancing the heat leak, cylinder flow, pumped circuit.

HTH Sam

 

[pioner]

sambotc
Well sam, I went up into the attic again this morning, and turned down the pump to No one, as you recommended, and while I was up there, I took a few more pictures, to try and let you see what is going on, then I lit the stove, and got a really fierce fire going with "Anthracite" as you will see in my pictures.

I must say, it is not a day for a big fire, as it is lovely/mild and sunny outside, but needs must.

after a while I could hear the water boiling in the stove, and the radiators started to get hot, but not as hot as yesterday, on No2, could the pump be raised by half. to one & a half, or doe's it only work on 1-2-or 3. ? as I feel we are not very far from a conclusion.

Regarding the gravity radiator, take a look at how mine is fitted, it is fitted as a normal radiator, and it also gets air locked,with only one side getting hot .

should the flow come in at the top, and the return out at the bottom, going to the vent pipe, ? as mine doe's not do that.

going back to what we discussed yesterday regarding using my lounge radiator as a heat link, I would rather not do that if there is any other way of sorting it out.

As you will see, there is Not enough space on the return pipe from my cylinder for either a gate valve or a motorised valve.

Cheers
pioner

 

[pioner]

Hi sambotc
sam, Hope you are well, as I have not heard from you for a while, I have again been thinking about how to harness the wasted heat from the domestic side of my stove, If you look at my third picture, (the one with two on) you will see the heating pipes going along the ceiling past the cylinder, close to the pump, what would, or Could happen, if I teed into the 28mm flow and return, before they go into the cylinder, and connect them to the 22mm flow and return on the heating pipes, would that be OK ?, and what size of pipe would you recommend ? 22mm or 15mm for the connection, so as not to take ALL the heat from the cylinder. would the pump have any influence on this connection ?

It seem's a shame to be wasting all that heat, when it could be put to better use making the stove CENTRAL HEATING as near perfect as I think you could get

 

[Norcon]

Don't make those connections what ever you do!

Have you tried shutting off the heat leak radiator as I advised earlier?

 

[pioner]

Hi norcon
good morning norcon, you tell me NOT to make these connections, but No reason why, I really do NOT need any connections at all to my cylinder in the first place, as i've said before, I heat ALL my domestic hot water with the emersion heater, in the cylinder, and alway's have done, I prefer it that way, (VERY SIMPLE) and I find it is cheaper. whether the heating is GAS or STOVE.

It is all about venting the system that I cannot get my head around, you must appreciate that I am losing an enormous amount of heat, that could be going to my radiators instead of my cylinder.

I would not mind some of the heat going to the cylinder (if it has to,) But NOT the ammount that is going at the moment, somone MUST have an idea how I can get round this problem, I am SO near to a nearly purfect heating system with my wood burning stove "HELP PLEASE" it is driving me mad.

pioner

 

[sambotc]

Hi pioner,

Sorry I haven't replied sooner.

Making those connections into the system won't work. You will also create a big probem as you will lose the majority of your gravity circulation. As said previously, it is possible to remove the cylinder, but the heat leak circuit would have to be increased dramatically. You could maybe have2- 3 radiators running on the gravity side.

Try tuning the system as both me and norcon have suggested, reduce flow through the heat leak, and if you add a gate valve on the cylinder return, this as well. DO NOT turn them off completely.

If you are able to push more heat around the pumped side, always check the system by turning the pump off and allowing the system to heat right up. A well desigend system should not alllow the stove to boil, although as your already does this, you will struggle!

HTH Sam

 

[pioner]

Hi sambotc,
I have noted what you have suggested. but I think I will have to settle for second best this time, as I could not, and would not want to move my cylinder to a different position .
I would like to thank you, and all, who have made any contributions to my predicament, I hate being beet, at anything. but this time, I come second. "THANKS AGAIN"

Cheers
pioner