Hot water to radiators???

[tmansteve]

Hi All

I have just installed my Solid fuel stove. I have plumbed the pipework so that we get hot water but after looking at some diagrams, I am puzzled about the connection for the radiators. It seems to be showing the connection straight to the boiler on my stove but if you did that, the water would be taken from the boiler and be cold in seconds as it would be in a loop allthough there is plenty of hot water in the cylinder.

If anyone has any info, I would really appreciate it. It has to be something I have missed or not as the case may be.

Steve

 

[Softus]

I don't understand your point about the water going cold.

Steve, you need to be a little bit careful with a solid fuel boiler, because the heat can't be instantly shut off, so there should always be a circuit that water can circulate around, whether it's through the cylinder or through one rad (or all rads).

If haven't followed the manufacturer's installation instructions to the letter, then read them again and correct anything that you've done differently.

If you have followed them then you shouldn't have a problem.

 

[tmansteve]

Hi Softus

It is very difficult to explain something over the net. The cold water feed is connected correctly to the stove boiler and the hot water outlet pipe is fitted correctly. The problem is this, when I connected the pipework for the radiators etc when you turn on the pump, the water flows from the stove boiler and you feel the pipe getting hot as it takes the water to the rads.

After a few seconds the pipe has gone cold because it has drawn all the water from the stoves boiler. All I want to know is how can you keep a constant heat when cold water is continually passing through the pipework. Do you have to have another cylinder to hold the hot water for the rads or is there something I have missed? I have installed the fire with the limited instructions I received. Plumbing the pipework isn't a problem as long as I know where the two pipes go for the rads. Is there a common distance from the boiler to the pipes etc????

 

[Softus]

We're not talking the same language yet Steve, but I'm sure that if we persevere then well get there.

Firstly, how many connections does the boiler have?

If two, then one of these, the "flow", should be taken to a pump, then either a three-port motorised zone valve or two two-port MZVs. In the latter case valves should be of the "sprung open" type, for the reason I mentioned earlier. From the valve(s) you should supply the flow to the cylinder coil and the flow to the radiators, and the return from each should meet before returning to the boiler.

If four pipes, then two are intended for a pumped radiator circuit and the others for a 'gravity' cylinder circuit.

In either scheme, water circulates through the boiler and the system gets hotter as time goes by - if it feels cold coming from the boiler then either it's being made to circulate too fast, or the boiler heat output is inadequate.

I'll pause here and let you reply to the above, to see what type of system you have and check that you've plumbed it correctly so far.

 

[tmansteve]

Hi Softus

Many thanks for your help so far. My system is gravity but the original plumbers did some shortcuts which I am now fixing. The o9ther thing is that it is 22mm piping and not 28mm. My boiler has 2 connections. The original piping is this :-

The pump is connected to the return so that damage was minimised to the pump but could easily be changed to the flow. At the flow end of the boiler, there is a tee piece and one pipe goes to the cylinder and the other to the radiators.

The hot water pipe to the cylinder is connected to the small expansion tank and will be changed so that it is an overflow and the cold water feed from the expansion tank will be connected accordingly.

I haven't fitted any valves yet and that is one thing I have forgotten. I understand the principles but anymore info about these valves would be terrific. All it needs is some clear info to help and you are doing just that. Look forward to your reply and any other questions you need anwering.

 

[Softus]

The hot water pipe to the cylinder is connected to the small expansion tank and will be changed so that it is an overflow and the cold water feed from the expansion tank will be connected accordingly.

I'm really sorry; I've read this several times and I don't understand it. Saying that a pipe is connected "to the cylinder" says hardly anything about it. Can you elaborate?

I haven't fitted any valves yet and that is one thing I have forgotten. I understand the principles but anymore info about these valves would be terrific.

Getting problem-solving help from the forum here is one thing, but guiding you through an entire installation is rather a tall order. Are you following any written information, either from the boiler manufacturer or somewhere else?

If you've made corrections to the work carried out by your installer then you must believe that he has made mistakes. What is this belief based on?

 

[tmansteve]

If you have an email address, I could send you the diagrams of my pipework.

What was installed before was a gas boiler. There was no overflow pipe and the water is gravity fed. The fire company showed me the way to install the fire and it is correct. The pipe work has been done as a solid fuel gravity feed. Similar to all plumbing diagrams.

 

[Softus]

If you have an email address, I could send you the diagrams of my pipework.

It would benefit everyone to see the diagrams, but if you're not comfortable with that then by all means Email them to me. My address is in my profile.

What was installed before was a gas boiler. There was no overflow pipe and the water is gravity fed.

I think we use the term "overflow pipe" to mean different things. Your diagram needs to show, amongst other things, a cold feed and a vent; the overflow from the cistern has no relevance to the performance of the heating system.

 

[Bigburn]

Softus wrote

[

i]two two-port MZVs. In the latter case valves should be of the "sprung open" type, [/i]

What happens if the valves jams shut or an electrical fault holds them shut ??.

 

[kevplumb]

where is the pipe stat and the injector tee

 

[Softus]

Are you just trying to pick an argument Bigburn?

 

[Bigburn]

Are you just trying to pick an argument Bigburn?

No not at all.

Can you give an answer to my question ? It may be beneficial to the OP.

 

[bster]

is it true that solid fuel systems require a PRV?

 

[Softus]

Can you give an answer to my question ? It may be beneficial to the OP.

The system should be designed to incorporate a heat sink to dump heat when demand ceases while the boiler is still producing energy.

If you're asking what happens when the designed-in fail safe devices and circuits fail, then the answer is that there's a problem. In your example (of two two-post valves being shut), then you're implying a double fault.

Or is there something else that you're angling at?

is it true that solid fuel systems require a PRV?

What pressure is being generated that you think requires a relief valve?

 

[tmansteve]

Well, from all that I have read so far, I have decided to get a plumber in to check my work so and take it from there. This is quite an issue with so many variables.

Thanks for all the help and will post when I have it up and running. Hopefully it will be a good outcome. I will keep you informed.