Linking multiple domestic boilers

tinski07

Hi All,
I have been trawling the web looking for answers regarding linked heating systems.
I am doing a big renovation on my home place and need some advice,

The house has currently has a back boiler stove and a firebird oil boiler which are simply tee'd into each other and a mix match of different types of pipes, pumps, valves etc etc etc.
Well I should say it had, It now has nothing what so ever. My plan is to upgrade the Solid fuel stove to become the primary heating (this is what I have in my current house and am very pleased with). But what I do miss is an automatic source of heat (When we are out in the evening or when the stove has gone out in the early morning) The firebird is my answer to that.

In addition to that I would like to fit a solid fuel range as it is something we would like and it would be multi purpose.
All are at ground level and the stove and oil boiler are on opposite ends of the building. The plumbing from the oil boiler will pass the range on route to the Hot water cylinder upstairs and the solid fuel stove would be direct to the cylinder.
So my thoughts at the moment are to tee in the range to the oil boiler pipes with non return valves where required. That would reduce my problem to two feeds which I guess would work with a dual core cylinder but then I cannot have the rads working off all systems.
I was thinking of perhaps a Spirozone unit at the tank to sort things out and take the rad supply from there or is it safe to build a manifold with non return valves ? The system will be vented.

On the other side of things I love the idea of a buffer tank owing to the fact that I could add a solar panel in future or if Oil prices went crazy I could change to an out door type solid fuel burner. They are quite costly though, If I had a buffer tank do I eliminate the hot water cylinder.

It needs to be a basic system, I don't want electronic valves and most likely all the radiators will remain on when ever the heating is on as its an old building and keeping it dry is paramount.

I have plumbed a few previous restorations, all vented basic systems but this one I will hopefully have to live with for a very long time and it is as such a blank canvas, as are my pockets by the way, so what ever I spend has to be carefully thought about.

Sorry for the long winded post but there's no point in giving anyone half the details.
So recommendations please !

scudo2

Yes.
We can send you a text on how to do all that safely without seeing it.



Sorry but you will need a GOOD experenced plumber to see it and plan it out.


Non return valves !!!!

Only a dual coil on a stove, oil boiler and a range !!!!

I'm not knocking your project, but there's quite a bit of technical experence required to do it safely and to get full performance from it.

Spend wisely, and do it right first time.
You mightn't get a second chance.

Dtp1979

+1. Absolute madness joining your range into the oil pipes like that.

mark_18tp

link all too a thermal store/ buffer would be ideal.

mark_18tp

but as it everyone says you need to get a experienced plumber too this, as to honest your plan sounds dangerous.

Outkast_IRE

mark_18tp wrote: »

link all too a thermal store/ buffer would be ideal.

I agree if this was my own house, a thermal store/buffer would be the route i would be taking.

tinski07

I'm not looking for a slagging just some clear answers on the use of a buffer vs Spirozone etc, Whether or not the range could be tee'd in ?
Its had an Oil range and later the oil boiler tee'd into the stove piping for 35 years without any issues so I'm wondering what the problem is with that.

I'm not talking about running all 3 together, at most the oil coming on in the early hours when the stove has died down.
I simply can not afford to be paying labour to a plumber and unfortunately I don't know any personally who could give me advice, Thankfully I know plenty of electricians for that part so hence why I am doing my home work on the plumbing.

The only difference in what I want and what I took out is the addition of a range. So why is teeing them in unacceptable ? I honestly want to know.

Could all three run safely to a Systemzone ? Can a Spirozone do the same job ?

What is the major danger with a vented system if the stove and/or range are self circulating with a heat sink radiator and the Oil boiler cannot operate without power anyway ?

I'm not looking to win any energy saving awards here so I can accept some loss of efficiency to save thousands on installation, think of that what you like. It is after all an old stone heat sapping building.

If I went for the buffer option what size is fitted to the average house ?

mark_18tp

I think you need a plumber to answer all those questions.

you may not be able to afford a plumber but I can't afford to give you answers, especially if they could potentially lead to a unqualified person installing a potentially dangerous system.

tinski07

Have you any experience with the systemzone, Buffers, accidents involving boilers ?
I have nothing done with regards to replumbing the place, I could just put back what was there with new pipework and get a non boiler range, I am simply wondering if it should be done a different way and why, and if possible could I add a range without putting me in financial ruin.

mark_18tp

you can add a number of heat sources with a buffer or thermal store. bring all to the store/buffer and then take from

you can have a buffer or thermal store with hot water heat exchangers built on

antoinolachtnai

If money is the main concern, I would concentrate on the oil boiler. It will make your heating system simpler and require less maintenance. When you take everything into account oil is fairly cheap and the future price of oil suggests it will stay that way. (The only exception is if you have a sustainable free or very cheap supply of firewood.)

If you want to invest to reduce oil dependency, which is a good idea, insulation is probably the way to go. You could spend 5 or 10 grand on fancy plumboiserie to get the stove working right, but you might be better investing in the fabric of the building. Stuff like better controls can save you 5 or 10 percent too. All these measures will help comfort as well as economy.

If you buy a lot of gear, like the stuff you are talking about, you really need the expertise to go with it. If you don't, there is a risk you will buy a lot of expensive gear and fittings, and then find that it doesn't really work right.

slavetothegrind

antoinolachtnai wrote: »

plumboiserie

i like it!

tinski07

Hi antoinolachtnai,
The majority of my budget is being spent on the building itself, The original building is stone and is being treated sensitively so it won't match any modern insulation standards but it will at least be healthy, The extensions are getting well insulated and the entire building rewired and replumbed. So as I will have borrowed all I can borrow for at least the next 5 years I have to spend it well, I also have to have it liveable before I run out.

I have decided to forget the range and just put in a non boiler one, I do have access to free solid fuel a good part of the time and I like being able to heat my house without depending on the outside world, A war in the wrong place etc could see the price of that oil change dramatically but as I have a boiler and at the moment prices are good why not enjoy the benefits.

I don't want to buy any fancy "plumboiserie".In fact I want it as simple as possible and I was looking for the easiest method of linking. I thought something like Systemzone might be it but I'm not really interested in zoning as I am just having either heat source heating all the rads.

As nearly every house I can think of has more than one boiler I didn't think it would be too much of a problem. I had a chat with a plumber who was working on a friends house yesterday and he is going to give me a plan for a basic vented system using a dual coil cylinder that I can draw up to suit my building and have him look over before I go ahead.

antoinolachtnai

The core problem isn't really having two heat sources, it's that one of the heat sources is solid fuel. There are a lot of risks with heating water with solid fuel, so you really have to be careful. The problem is that you can't quickly damp down a solid fuel fire if the water gets too hot. You have to have tanks, one-inch copper pipes and other fittings that you can depend upon to deal with excess heat. If the excess heat isn't dealt with, someone using the taps might end up scalded from superheated water. Your local plumber will be able to explain the whole thing to you a bit better. You should also ask about the costs.

It's a matter of approach really. Hardly any house I know nowadays has more than one heat source and that heat source is gas or oil, so the source is very controllable. That's just because I live in the city rather than the country and probably because the houses I look at are a bit newer and smaller. (Though now that I think of it, one house I know, built in 1980, which has a back boiler, but it has not been used in at least 20 years.)

I think the reason they don't do it anymore in the city is that oil and gas boilers have become so reliable, fuel has stayed cheap and the systems can be very simple. The system can be sealed, and this makes it that bit easier to maintain and makes it a bit more fuel-efficient. 3/4 inch qualpex can be used for most of the plumbing, rather than copper, so that keeps costs down too, both for buying the stuff and installing it. The result of this approach is that plumbing of modern heating systems is actually pretty inexpensive.

You can still plumb it the old way too, but you won't have these advantages. But you would have the advantage of having a solid fuel boiler on there. The one thing you can't do is combine bits of both approaches and just hope for the best.

tinski07

Thanks antoinolachtnai,
I am indeed in the country and it does seem that more or less every one I can think off has a solid fuel as well as oil or gas for convenience. I would be quite comfortable with the solid fuel and vented system side of it, It is a two story house with a good rise to the tank, It previously only required the pump to send water to the radiators but since the new stove will be a bit bigger I will fit a gravity fed radiator in the system and the cylinder will be a slightly larger one. I realise it needs a completely unrestricted flow to the tank and copper piping, I measured out where I will fit the cylinder today and I will have a total of 4.5mtrs between the tank and stove which I believe is quite acceptable.

The oil boiler on the other hand is 9 meters away, I need to know whether that will be an issue and I also have 2 choices for running the pipes from that, One is drop down and bury under a new floor then up and through what would once have been a small north facing window which is now in the extension attic to the cylinder or alternatively I can go straight up and all the way along through the attic and straight through into the Cylinder. A few of the advantages to that would be its much more straight forward and the pipes could also rise all the way to the tank. My expansion pipe from the oil burner can also take this route and up over to the expansion tank. The Cylinder being in the stone building means placing it inside what is now a bricked up window is by far the thinnest part of the wall to get anything through.

I'm guessing mains gas in the city makes gas all the more convenient. I must have a look at what was done in my Grandmothers 1991 bungalow out of interest, That has a gas boiler, the kitchen fire place also heats everything and there are pipes in the living room to allow a boiler in there as well !!

antoinolachtnai

I see this solution for having a sealed and open-vent system working in conjunction with one another: http://systemlink.ie/products-59/plate-heat-exchangers.html

One observation about this - in my experience, heat exchangers are expensive and have a limited lifespan (say 20 years) then they start to leak slightly. But really this goes for just about all the bits in the system, tanks, coils and so on. The less 'bits' you can have the better.

The thing about the modern systems is that they have relatively few 'bits' in them, and they are concentrated in a small number of locations on the system. As you get more complicated, you end up with more 'bits' and more locations. That is what drives up the cost of fitting them and then maintaining and replacing them.

I had an open system replaced with a sealed system with a new boiler in my parents house last year. It is a fabulous improvement. It is just the small things really. The radiators don't need bleeding which used to be a yearly or twice-yearly ceremony. Not having a roof tank makes it a lot easier to keep an eye on all the bits of the system. The modern boiler, with no roof tank to heat and set up to maximise the benefit of condensing, gives a lot more comfort for the same amount of gas.