Evening all

Our house (100 year old farmhouse) which we moved into a couple of years ago came complete Thermal Store water hot water / central heating system from McDonald Engineers.

The previous owners installed the system so that the sole heat source is a solid fuel Rayburn which is also the only built in oven / hob. Madness.

To say that its been a challenge keeping the house nice and warm during the winter is a bit of an understatement. If the fire in the Rayburn goes out, say when we go away for the weekend, we return to a freezing cold house. We could leave the immersion heater on but that would be eye wateringly expensive. Also, when you a run a bath the temperature in the thermal store drops so the radiators go off until such time the Rayburn has heated the water up again.

During the summer when we do not want a kitchen heated to the temperature of the sun by the Rayburn we let it go out, eat salads and suck up the cost of the immersion heater.

So – does anyone else have such a system and if so what heat sources have you got feeding the thermal store? We are thinking of adding a boiler of some description to the system which will at least allow us to have hot water during the summer and prevent the house freezing if we go away during the winter.

(I’m expecting vast amounts of tumbleweed to blow through this thread BTW!)

Stoner is the man eg http://singletrackworld.com/forum/topic/solar-water-heating

EDIT: Thanks Murray, posts crossed in writing!

Yes I have one.
They’re fantastic. I think all new houses should have one…because…..

think of it like an energy battery. You can plug in all the sources of heat energy you like, and depending on the seasons and fuel costs use the most efficient.

Mine has a solar coil at the bottom, the primary circuit is to my boiler (biomass) and there’s an immersion for DHW top-up in the transitional seasons when solar thermal isnt pulling it’s weight but I dont want to fire the biomass boiler.

In your case, your rayburn is the sole source of energy. That’s not great. You should add solar thermal for summer DHW (without having to have a got rayburn running) and then your immersion is used for April/Sept top up before you need central heating.

As for heating your house when you’re away, well that’s tricky.
You can use the immersion, controlled say but some remote system like Hive. Or you need an alternative better value called-for-heat boiler such as oil or biomass pellet.

Rather depends on your appetite for spending stupid amounts of money 🙂

Id say go thermal to start with, and smartarse controller on your immersion for special occasions.

Cheers Stoner, that’s really useful.

I’m off to investigate some smart way of controlling the immersion heater as a short term solution.

For the complete solution I think we would need Solar and an oil boiler so that in the winter when we are all wanting a bath or shower we aren’t reliant on the sun. We are in Aberdeenshire so it gets dark early!

Thanks again for the info.

My comes have one. Solar thermal works in the summer, the old gas boiler is piped in to allow for top up heat, wood burner in the winter and immersion heater has a final back up. An excellent system.

Google WiFi enabled relays / contactor’s initially so you can turn your immersion on remotely as a simple solution for when you are away.

Sold a McDonal thermal store to a customer in November. The only thing is it may not even have the trappings to add solar in, in which case you’d be in for an even bigger bill as if you wanted to stick with a thermal store you may need a new one. McDonald are pretty good though so you may be able to contact them and get them to add them. Although that would mean getting your tank to Glenrothes and back!

^ that’s true.

One would hope it had a coil or two in your existing one….

If not, it’s just a hot water cylinder.

Move aside Stoner…….

No he’s pretty correct, but you also need to make sure you have a store that will accept multiple heat sources.

the other thing is you will need to ensure that it is piped up correctly, probably using some kind of split arrangement so that you don’t run out of hot water when all the heating has been on. Often the top part is dedicated to the hot water side and the heating the lower part.

also not all thermal stores are equal, some have baffles in which prevent the water becoming an even temperature.

probably the best bet would be a simple boiler connected to it for summer / emergency use.

ah, there you are.

Thought you’d retired 🙂

We’ve got one connected to a ground source heat pump. House is heated by underfloor and tank is for DHW only. It takes priority over heating and gets heated pretty well in about 30 – 45 minutes then switches back to heating. Unfortunately we have found that it is basically too small for the house and we can rarely get even two showers from it before all the heat is gone. No room for a bigger tank, so we’re a bit stuck.

We’re in Aberdeenshire too.

Our tank has an unused coil in it.

We had the plumber who installed the system over to do some work for us and he told us that the previous owner (who had the system installed) was adamant that he would never need a secondary heat source, i.e oil, and the Rayburn would work just fine on its own.

The plumbers thought he was nuts so they ignored him and installed the system so that another heat source could be added at a later date when the owner saw sense, or someone else bought the house.

the other thing is you will need to ensure that it is piped up correctly, probably using some kind of split arrangement so that you don’t run out of hot water when all the heating has been on. Often the top part is dedicated to the hot water side and the heating the lower part.

We never run out of hot water when the heating has been on but the radiators do go off when we have been running the hot water. Does that sound right?

We have cut down on hot water use by having a massive kettle sat on the side of the Rayburn all the time so we can use that for washing up and the shower head is one of these eco jobs which uses less water than standard one.

radiators do go off when we have been running the hot water

how do you mean?
the pump stops running? or the water supply is too cold?
Where is DHW taken from the store, where is the CH circuit taken form the store?

Id ask the installing plumber about it.

The pump on the CH cuts out when the temperature of the thermal store drops to a certain level.

Water is still piping hot from the taps at that point though.

I’m assuming that the the DHW comes from the body of water in the tank which the rayburn has heated up via the sealed circuit passing through the back of the rayburn and through the water tank. When the hot tap is turned on the pump out in our steading kicks in and draws water from the well. We don’t actually store any water, only that which held in the pipes and in the cistern of the toilet.

Beakers
We have the exact same system and the exact same issue
No problem keeping the house warm, it’s too hot most of the time. But if you go away it can take 3-4 days to get it warmed through again, the house is the thermal mass. I don’t have any trouble banking the fire up and damping it down it will go 10 hours without refuelling
Rayburn make a eco-connect system to allow and control a second heat source. It defaults to the renewable source (solid fuel)
It’s expensive though and no doubt some one with the necessary knowledge could do something similar
You can’t compare an house with no insulation and solid wall to a modern insulated building with cavities. Obviously you want to control costs it’s a case of finding the best compromise for you
IMHO it is an old fashioned system, but very effective at keeping you warm but it needs more control to be comfortable in spring/autumn

Hi Beamers, i have installed a fair number of these in the highlands.

They are made to order to suit the situation in which they are to be installed so a photo of yours would help so i can tell you your options.

The hot water is usually mains fed through a coil and then through a mixer valve at the other end to reduce the temp. The rayburn heats the main bulk of water directly. The spare coil can be used for a sealed system boiler although it might not be a coil, unless you have the drawing which usually comes with it to confirm?

Always better to have some form of timed automatically ignited heatsource as the tank should sit at a constant 75-80 degrees c.

I’ve just spent the weekend stoking the neighbour’s Rayburn while he was a away. That is not a euphemism.

@ beaker2135:

I don’t have any trouble banking the fire up and damping it down it will go 10 hours without refuelling

What’s your technique for achieving 10 hours between refuelling? Is your Rayburn still producing enough heat to get the radiators to come on during that period?

@ supremebean – I do’t think we were given the drawing by the previous owner. He was pretty clueless about the whole system TBH having only lived with it for a couple of months (late summer / autumn). I don’t think he had had the chance to work out how to use it properly. I’ll drop you an e-mail with a couple of pictures or a video clip showing the tank and current pipework, it that’s OK.

Hi Beamers, Yeah no probs fire away!

No secret, riddle it and empty ash pan, fill with local anthracite to bottom of the fire box door, shut spin wheel on ash box door and open a quarter turn, shut flue damper and turn thermostat to one
Obviously it cools down, it would be too cool to cook on, radiators cool as well but the house stays warm and the hot water is piping hot
Would be better if it was filled more regularly, but if you have to go out or over night it’s fine. We’ve looked at swapping for oil or gas but it’s so nice to have the house so warm 24/7 that I think we’ll go Eco connect with a gas boiler for spring/Autumn and when we’re away
When we moved in two years ago we couldn’t get on with it so we had it serviced, the main problem was the thermostat was bust, much bett with one that works. Only other thing is it needs cleaning ever 4-6 weeks to keep it burning properly, especially if we burn ovoids

Must get round to solar water – any decent plumbers / solar water fitters round York?

I’d be disappointed if you didn’t at least look at doing it yourself 🙂

http://solarproject.co.uk

I’ve looked. I love the idea of doing it myself, and I probably could, but experience tells me that I run out of time very quickly.

Also I think I need a heatstore with more inlets, which starts to get messy. Decent professionals would just do it faster, cleaner and based on other jobs not that much more expensive by the time I’ve factored in roof access, tools and shifting things like heatstores.

@ beaker2135 – That pretty much mirrors our routine for overnight. We live in a pretty exposed location though so when it’s windy we have to close the flue damper as we can end up with the smoke coming out into the kitchen as the flue cools down and the draw drops off.

We use ovoids for overnight and during the day we have been using house coal. Quite mucky but it burns really hot and consistently.

I’ve also been experimenting with those verso heat logs which are currently half price in Home Bargains for day use and they seem to work quite well.

It’s like having another child in the house though. We are anyways thinking “what’s the Rayburn doing, i.e what time are we eating, when did we last or fuel in it, etc, etc.”

t’s like having another child in the house though. We are anyways thinking “what’s the Rayburn doing, i.e what time are we eating, when did we last or fuel in it, etc, etc.”

LOL I know what you mean, at least we have alternate cooking arrangements. I quite enjoy it though or that’s what I tell myself

Luckily our flue draws really well, at least now I have taken the short piece of 4″ gas liner out it doesn’t roar like a jet engine!
I’m not keen on ovoids, they cost more, smell more and clog up the flue throat at the back of the fire box, they don’t makes as much clinker though. I’ve been experimenting with a mix of 25-30% ovoids in with the anthracite, I not convinced though
I’ve not come across the verso logs I’ll have a look
The guy that lived here before us ran it on logs, it must have been a full time job 🙂

I quite enjoy it though or that’s what I tell myself

We have a love / hate relationship with ours. Low points have been when through user error (massive log on embers combined with a hurricane outside / not cleaning out the debris post chimney sweep) we have had a kitchen full of smoke. By full I mean dense choking smoke down to knee level!

All good at the moment though as the weather is cold and we, well I, have managed to get it to work properly after a couple of years of trial and error.

I ordered a couple of cubic meters of logs at the end of last year and ran it off of those during the day time. It was a full time job carting the logs in, stacking them up next to the rayburn and then feeding the fire on a very frequent basis.

You should check out those heat logs. They last ages and are conveniently sized and packaged:

Verdo Heat Logs

Beamers, rather than solar thermal you’re better off installing a solar PV system.
We have it and use a proportional immersion controller (such as an immersun, but there a number of cheaper ones that work just as well) to send spare solar generation directly to our immersion heater. Once the immersion is at max temperature you can then send the spare power to another resistive target such as a thermal store, another immersion, a storage heater, etc – or just let it go out onto the grid.

The result is that from May to Sept there is nearly always a full tank of hot water by 8am. Obviously it also contributes to your daily power usage also which solar thermal does not plus you don’t have to mess with water up in your roof space. You also get some money back in the form of FIT payments but they’ve been slashed recently so it’s not quite the no-brainer it used to be.

There’s a ton of great information on this sort of thing over on the Navitron forums,
Solar thermal is pretty good but it’s had its day.

Having worked for ME for 12 years, up to 2007, I would say that you need to give them a call. The unit will have. A badge with a production number, and they will be able to get the drawing reprinted for you and advise what connections are what.

If the badge is missing, look for the number in marker pen, somewhere on the insulation.

Till then, the advice from bear/stoner et al is reasonable.

Cheers Beamer the Verdo logs look good but access is the problem for buying in bulk. The coal man has to come in a hi-lux, so we’d have to hand ball them from the road. Otherwise I might of considered a bio mass boiler

Have fun and stay warm 🙂

We use ovoids for overnight and during the day we have been using house coal.

IME…

(although bear in mind we got rid of our aga-a-like range, and fitted a TRG boiler – which is a massive, massive improvement)

ovoids were ok – chuck on a massive load, close down as much as possible, and it was usually juuuuust about still going the following morning. just. but not reliably.

anthracite was best – once you get used to the fact you need a real big pile of it in the grate, otherwise it goes out. much more consistent burns.

avoid house coal at all costs – it’ll make a complete mess of your flue and the inside of the range and you’ll have a nightmare cleaning it out.

wood, no chance, far too manual, will never bank down, loads are too inconsistent. Fine for hobby fires in the lounge when the central heating is on, or if you run a batch burner, definitely not for the aga though.

we’ve got a multifuel in the lounge which is our main heat source in autumn or spring when it gets a bit milder, anthracite is the first choice for that too.

when it’s windy we have to close the flue damper as we can end up with the smoke coming out into the kitchen as the flue cools down and the draw drops off.

This sounds like you’ve got an issue with the chimney, if you don’t already have one it might be worth trying an anti downdraft cap – you should never get reversed flow while the fire is going no matter what the damper setting.

wood… Fine for hobby fires

It’s our only source of heat! I previously lived in a farmhouse with a Rayburn range that was also the only source of hot water and we only ever fueled that with wood.

Aren’t ovoids and anthracite one and the same, i.e. ovoids made of anthracite?

Not sure what ovoids are made of except that it is type of coal mixed, as far as I know, with cement dust and that is what you’re left with and what clogs the chimney.
Again as far as I understand anthracite is a high quality coal that burns hot and clean which is why they use it for steam engines. It helps that we have a pit in town that still mines anthracite so it’s cheaper anyway £13.50 a bag

Not sure what ovoids are made of except that it is type of coal mixed, as far as I know, with cement dust and that is what you’re left with and what clogs the chimney.

Mostly anthracite, some lower grades, plus a bit of binding agent, sugar or similar. I don’t know about cement dust, I think that’s barbeque nuggets. The lower grade coal and binding agent seems make it a bit easier to light & burn as compared to anthracite. Anthracite is usually a bit cheaper than smokeless ovoids IME.