Combining an Esse Range, Oil Boiler and Thermal Store?

[JGF]

Hello all,

First time on this forum so appologies if this question has been asked a million times before!

Currently renovating a property which includes installing a complete new CH system. Only real fuel option is oil, but we've bought an Esse W35 (wood fuel) intended to substitute oil use.
As we dont expext to run the Esse continuosly, I'm thinking an Akvaterm for storage of energy from the Esse which would be topped up using the oil boiler (or visa versa).

To date I've asked 4 different plumbers and had 4 different answers about the set up of the system (in fact one guy said it can't be done!) so I'm starting to worry that the system may be unworkable.

As a rank novice to this field, I'd be very gratefull of any advice / information / course of action on the subject. Even better, has anyone here installed a similar system?

Many thanks in advance.

J

[Fintray]

JGF

Welcome to the forum; whilst I do not have such a system yet, there are many on here that have and will be along with advice to help you. 

[dhaslam]

There isn't anything  particularly difficult  about that setup.   The store needs to be a decent size for several reasons.    It needs to act as a buffer for the woodstove, it needs to have  separate capacity at the top for DHW  and you should leave some provision at the bottom for future solar  input.    The woodstove will heat the store from the top, i.e. the output from the  stove goes to the  top input on the store.   You can use a  load valve system to ensure that the  return to the stove is hot.     The oil boiler is connected lower down and  should be set to  come on when radiators are needed but the store is  not hot all the way down to the  radiator talkeoff point.     Domestic hot water normally  is heated by passing through a coil or  more usually two coils  with most of the heat transferred from the hotter upper coil.        

[Brandon]

as above, no trouble doing that at all.

 ask away.

[tarrel]

Hello,

New to the forum, so please bear with me..

@dshaslam:

"The oil boiler is connected lower down and  should be set to  come on when radiators are needed but the store is  not hot all the way down to the  radiator talkeoff point"

Do you have any thoughts on how to do this?  I'm guessing there would need to be some form of tank thermostat located at a particular point on the tank and connected into the boiler's controls?

I am looking to do something similar to original poster, using the "central heating" side of our existing Grant oil-fired combi-boiler.  The boiler would be used to support solar when needed, and for the "ill in bed" scenario when firing up the stove is impractical.

Thanks

Tarrel

[dhaslam]

Assuming that the  store has fixed insulation and there  isn't  a suitable sensor pocket  in the correct place  you can remove  a piece of the insulation, insert the remote sensor for  a thermostat and cover it up again.  This will give a reading a few degrees lower than the water temperature at that point.    The thermostat  should be placed   below the radiator outlet and inside  the area that is heated by the   boiler coil.     The thermostat then has to be wired to the   boiler after the normal time controls for the boiler.   The time controls can be set for  a fairly long period that covers the hours when the  stove is normally running because it will only operate when the store is cold. 

[tarrel]

Ok.  Understand.  Thanks very much.

[Solal]

Remember a thermal store  will  have  inferior  dhw water  delivery rates in comparison  to an unvented cylinder.
They also utilise less  solar  enery due  to  the inefficiency  of instantaneous  heat transfer  across a heat exchanger.
They  sludge up and encourage  sludging  build up.

Sealed systems  are the way to go. DHW delivered directly  from the cylinder  and solid fuel connected to  unvented cylinders. The europeans have been  doing it for years. They know best. Especially the Germans.