Does anyone have practical experience of fitting one.
I have been trepidating over ordering a log burner with CH boiler basically because I suspect the coil on my existing hot tank is too low for either version of the neutraliser to work under gravity alone.
Raising the tank is not very practical as it would then bulge into the loft. A second hot tank could be installed but with what benefit?
As a sideways step I have ordered a log burner which can have a CH boiler retro-fitted while I seek counsel:-)
Hi Tim I fitted one some 15+ years ago. It's a challenge plumbingwise if you've got only a small space; a plumber doing it would take in a long suck of air and warm up his calculator. May well be easier with modern plastic pipes.
My ceiling height is nominally 9ft and I've got the tank on a frame such that it's base is 6.5ft above the floor and it just pokes through the attic floor (with a cupboard above for wine making and the CH header on top of that!). I'm not sure quite what counts as the head above the stove but the bottom of the saddle tank is about 10" above floor level.
Does that help - by all means come back with any questions.
This is a two storey farmhouse with an *included attic* construction so in most places upstairs I can easily lay a hand flat on the ceiling.
The intended boiler position is almost directly below the airing cupboard and, at a pinch, I can bring the gravity riser in at floor level.
My existing hot tank stands on the floor and terminates just below the ceiling! Immersion heaters have to be fitted from the loft.
My first stumbling block is failing to understand the neutraliser installation instructions downloaded from their website. For instance boilers are categorised into 4 classes without explaining whether this refers to the existing boiler or the one you wish to add!
As Dunsley seem willing to get involved in the system design, I should perhaps write to them explaining my intentions and see if they can clarify things.
It is reassuring to know that someone has a successful installation:-)
Firstly I've found the boiler classification from my old datasheet:-
1 Solid fuel boiler not controlled by a water sensing thermostat
2 Ditto controlled
3 Conventional gas/oil fired boilers with low resistance heat exchangers
4 Low water content, high resistance gas boilers.
I'm a bit puzzled as to your concern about the height of your tank coil; I haven't explored the Dunsley website extensively and I may have missed something but what I did see was that a head of 350mm is quoted as the minimum. On the basis of that I think it is reasonable to assume they mean above the top of the stove, or at least the centre of the output pipes
If I understand your house description the tank is sitting on the upper storey floor, ie some 7/8 ft above the ground floor where the wood burner will be. I've measured my set up and there's 1.25m from the stove outlet to the bottom of the R type Neutraliser.
I was advised against the complex plumbing arrangement that Dunsley show on their site and in the leaflet I have. They are keen in both on the accelerated gravitational flow system involving an injection T. I just used 28mm pipe - mine's a type 1 boiler so I rely on the ordinary vented tank to be the dump - over 20 years use and there's never been a problem. What I do have is a home brewed differential thermostat on the stove and some electronic logic to shut off the oil burner when the wood stove is up to temperature.
Right! Does this refer to the existing CH boiler or the one you are trying to link up? My existing is a Potterton Profile which I guess comes into the conventional gas/oil fired boiler with low resistance heat exchanger category 3.
Yes. I will have a gravity head of about 6ft.
OK I am a bit concerned that the return from the tank coil is very close to the floor. Fitting a towel rail would be simple enough.
er... do you not have motorised valves routing water into the coil or CH or both? I suppose this is their fancy electrically fail open valve.
I really need to study this much more carefully in order to ask sensible questions. Thanks.
heatbanks wasn't universal and this was the accepted solution AFAIK. It works for me. BUT, and this may well be relevent to the OP too, the problem is the lack of head generally in small older properties to drive hot water at a useable pressure.
I have been looking at converting my system to a heatbank configuration, as the electric shower is only just acceptable in the winter and the extending mixer tap in the kitchen is a joke, all because this is a single storey farm cottage.
Oil CH boiler (type 3) goes in one set of ports, uncontrolled wood burner (type 1) goes in second set of ports.
One motorised valve in feed to tank only - driven closed when CH is called for and the CH pump is running. If I remember rightly the logic makes sure that all heat using sources are available if the wood burner gets hot. I seem also to remember that 'electrically fail open valve' is the norm.
I would support DD's comment that you might well also consider the heatbank arrangement. The Neutraliser is a mini heatbank in reality, and the cost and complexity of fitting might well be put to giving you mains pressure hotwater too.
their explanatory diagrams do not display legibly in my version of Explorer.
Prevention of *boiling* is fundamental to any unattended solid fuel appliance but this is the first time I have seen mains cold water, run to waste, suggested as an overheat prevention measure.
An initial reaction is concern at the number of additional pumps! I find my existing system, run all year on demand, needs a new pump every 6 years. Currently I am changing to the adaptive version in the hope of quieter operation near control temperature and better pump life.
that a simple neutraliser and associated controls is likely to be much cheaper as a retro-fit. Where was your system when we were making decisions in 1994?
The intial stage is run the DHW pump through the plate heat X as this takes hot water from the top of the cylinder to the bottom. Next stage can be running the CH. Third, dumping mains water. (this is poorly mechanical so should work when electrical outage)
A good pump should last 10 years minium if fitted properly. Cheap pumps dop't last.
There were there. By fitting one now, or converting the existing cylinder which is a cheap way, you instantly get a state-of-the-art system and bang up to date. The benefits are immense. Do not underestimate the buffer effect for CH, of a heat bank. A Dunsley is not cheap and does little. The DHW was taken off via an immersed coil. Look at the Navitron web site and forum. They have many there who use solar panels and solid fuel with heat banks.
formatting link
the words, heat bank, into the search and lots comes up.
Hey, hey - cable brakes ***were** a joke; I don't know how old you are but I'm old enough to have driven all over the continent in a car with cable brakes and you had to tweak them up every other day to avoid going over the edge on an Alpine pass.
The Dunsley may not be the most elegant solution from your point of view but it does the job that is required of it - without any adjustment.
DD writes ">A good pump should last 10 years minium if fitted properly. Cheap pumps
Well I've been lucky then, or by good fortune fitted the pumps properly, as I've just been back to my old notebooks and the pumps have been in now since late 1988, and I wouldn't have had the cash then to go for gold plated ones.
It could of course well be that operating to and from the neutral point of the Dunsley reduces stress on the pumps .... possibly!!
In that case I would suggest you duck out of this complication - in fact having seen what inexperienced users do to log burners, I would duck out of that too; recently been to two places where the log stoves had been b******d by users not knowing how to use them.
The original purpose of the log burner was to offset some of the cost of gas heating; by putting heat into an open plan area. At present, the rambling nature of a T shaped development, lots of external wall and insulation to mid '90's standard mean that a conventional 100.000Btu boiler struggles to change the building temperature.
Clean burn with wood and a *wrap around* boiler is a bit of a contradiction that even the manufacturers hint at. The original plan to provide most of DHW and CH during the evening from logs looks very uncertain. Expecting tenants to return from work and light log fires is hopeful in the extreme:-)
At present, we inefficiently burn logs on an open fire for Winter evenings. The immediate plan is to instal a large log burner in the centre of the house and gain some experience of whether this makes that particular room untenable and how heat dissipates elsewhere in the building. With the benefit of advice from here, consider retro-fitting either a 10,000Btu or 27,000Btu boiler and linking to the existing system.
By the time we get to tenants, the main boiler will probably be condensing, some of the load will have been diverted due to building alterations and BG will have lowered their tariff:-)
Hmm.. This is a fairly big system; 21 radiators all fitted with TRV's except two on bypass. The pump becomes noisy as the system reaches temperature, particularly on overrun and hence the change to the adaptive type.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.