Please put me at ease

[festive]

Ok I have a log burner with back burner being installed next week. The hetas engineer is qualified for back burner log burners. Its being connected to my new heat store by the plumber on the day. Log burner man is fitting a new liner connecting the chimney (Not water the plumber is doing that) and adding some steel heat shield (shouldn't it be non conductor like fibre board) plus a cap on chimney 1000 pounds for 2 men for day install.

I can't help but feel this is quite a bit considering I paid the plumber about 1400 Labour to install a new boiler and heat store about 7days here. Thoughts justifications ?!

 

[muggles]

Sounds too cheap to me. I'm normally around £1500 to reline a chimney and connect a stove. What quality liner are they using? No doubt for that price it'll be the cheapest lowest quality one they can find.

Is your plumber qualified & experienced to install pipework onto solid fuel back boilers? Does he know what safety features are required?

 

[festive]

Ah ok.. Well we are adding a loop with a 3kw rad which is in effect a heat sink to bleed off excess heat in th event of any issues.

 

[muggles]

Well that's a start. You also need a correctly rated loft tank, pipe thermostats and an injector tee if you have a pump on the circuit, all pipework needs to rise continuously in minimum 28mm diameter pipe with no tight elbows - it must be swept bends - and so on and so forth.

 

[Nige F]

Ah ok.. Well we are adding a loop with a 3kw rad which is in effect a heat sink to bleed off excess heat in the event of any issues.

On a gravity circuit presumably ? Then you'll need 3/4 inch tappings for it to work - it'll struggle on 1/2 inch.

 

[festive]

Hmm using two tap circuit. You mean 3/4 from log burner to heat store or 3/4 for the heat leak circuit?
Not heard the mention of an injector tee. But see it here on the working diagram from Parker ray install instruction. Yes we are having a metal header tank installed snuggles.

 

[lostinthelight]

Out of interest, How many Btu’s does the wood burner supply to the hot water?

 

[festive]

Heat Output To Room 5Kw
Heat Output To Water 11.3Kw

220Litre thermal store

 

[muggles]

Hmm using two tap circuit. You mean 3/4 from log burner to heat store or 3/4 for the heat leak circuit?
Not heard the mention of an injector tee. But see it here on the working diagram from Parker ray install instruction. Yes we are having a metal header tank installed snuggles.

¾" for the heat leak circuit - 22mm pipe and ideally a radiator with ¾" tappings, although ½" is acceptable with a maximum of 300mm of 15mm pipe running into it. Make sure you get high flow lockshield valves though, and it should ideally be piped TBOE. Pipework from the stove to the store should be 28mm. Your loft tank should have a copper float, as plastic ones can melt. An ESBE load unit is an alternative installation method

 

[festive]

Thanks Muggles appreciate your expertise here. Defo bringing a metal tank as the log burner man pulled up on this and insisted on a metal one, i will politely 'enquire' the above is being adhered to though.

 

[festive]

Got everything running last night, log burner getting hot pipes flow return hot. Seems the boiler still kicking in alot, which is apparently so, i was under the impression the stat on the heat store decided wether or not to fire up boiler if room stat is saying the house is too cold but plumber reliably i am sure informs me the boiler will still come on anyway?! Im none the wise here what our log burning back boiler will contribute. Didnt really want to spend 10k if it takes me 20years to make any saving. /

 

[festive]

So leading on from that... I checked the wiring tonight. Looks like the thermostat near the bottom of the heat store controls the closed loop valve I guess to help heat the water quicker from boiler?

I see no other thermostat for boiler. My concern is when the Log burner is running what's telling my oil boiler to switch off registering that the heat store is hot enough.

I think my main concern here is our system 'seems' to be wired as a conventional boiler/rad circuit. Does anyone have any wiring examples of a Heastore/Boiler circuit so i can compare?

 

[oilhead]

I have no diagrams, but if boiler is feeding heatstore, along with the wood burner, then a thermostat on the heatstore would control the boiler. If there is no interlock between the heatstore and the boiler, then the boiler will run on its own stat and cycle. What temperature is the heatstore loop stat set at compared to your boiler stat? A bit of experimenting with the boiler stat when the logburner is running may reduce boiler run time. Also do you only have 1 circulating pump through the boiler and heatstore, or do you have separate pumps for the boiler to heatstore, and the heatstore/radiator circuit?

 

[festive]

Hi Oilhead i started to look at the wiring diagram, and reassuring you've said that. Initial glance of wiring i have the following observations:

Heat store stat is wired inline to one of the ZVA (Drayton Zone valves) therefore i assume it closes circuit when the heat store is below temp to bypass central loop and boost heat direct to heat store for hot water from boiler?

Room stat seems to switch feed from timer to switched live on boiler and CH pump?

There is only one pump which is on CH system which pushes.

Where would the boiler stat be set, we have an 18/25external worcestor bosch i gather you mean its a setting under the hood there?

Thermal store stat is set to 80 degress but as above only seems to activate loop.

Two crucial things you mentioned here i feel should be vital:

The boiler is not linked to heat store thermostat

There is no separate pump for CH when boiler is off not running, the pump on my system is powered from switched live on boiler.

 

[muggles]

Sounds to me like he's not got the correct controls on there.