Hot water thermostat needs fitting, gravity fed back boiler.

[ywsian]

I have a gravity fed back boiler set up, but there is no thermostat on the hot water side, so as you can imagine the hot water is scolding hot when its run.
There isn't a thermostat on the central heating side either, just controlled via a Honeywell ST7100 programme timer.

The cylinder is directly above the boiler (well, up in the bedroom), so i would imagine that the fitting should be quite easy to do.

What sort of price should I be looking at for fitting a hot water thermostat?

Also, a rough price for fitting an RF type room thermostat for the central heating?

If anyone is local to Doncaster and fancies having a go.... let me know

 

[weareleeds]

No point fitting a stat unless it controls something ie a zone valve on dhw return.If bbf is reasonably new ( up to 7 to 10 years or so) you would be better fully pumping system (approx £900) or else wait & get a combi

 

[Digiteeruk]

I came across this excellent site with a fantastic diagram describing how the two types of stat wiring works:
http://www.gasman.fsbusiness.co.uk/gravity_hot_water_pumped_heating.htm
As you can see, its simpler than you thought!
However, I have a Gravity system (see previous post) in need of updating and the advice from everyone so far has been to make it at least fully pumped (see here: http://www.gasman.fsbusiness.co.uk/fully_pumped_systems.htm )

Regards
Dig

 

[ywsian]

Great pic from the link Dig

Ours is the same system (gravity hot water/pumped heating)

So, from looking at the link, the job doesn't seem as big a job as first thought.
Is it just a case of fitting a zone valve and a anti-gravity valve?

Wonder what difference that makes to the previous quote? If any?

 

[Digiteeruk]

Well, there is no doubt that fully pumping is more efficient, however I have calculated that it will take a number of years at least to pay back the repiping costs before you start saving if you have a contractor do it.

If cost is an issue, the zone valve would thus be the way to go I suppose

Alternatively, a friend has just helped out someone who had nothing to spend at all for a while by isolating the gravity HW from the boiler so that the boiler is only pumping to the CH and using the electric immersion for HW!!

Are you sure that there isn't a stat bulit into your programmer? How is room temp controlled?

Regards
Dig

 

[ywsian]

There is no room temp control at all on the system or on the programmer.
The heating is either on full blast or off.
Controlling the temp in the room isn't that important really as we usually switch it off when we get too hot.

My main concern is controlling the water temp, not only because of the obvious in someone might get scolded, but as I am in the middle of revamping the downstairs w/c, i'm wanting to use plastic pipe (speedfit)and pushfit fittings (cuprofit). The stuff I have is for central heating and hot water upto 82 deg/c (the fitting are upto 95 deg/c).

I suppose the easiest thing to do would be to stik a thermometer under the tap and see what the actual temp of the hot water is.
If it's around 82 then it may be a case of using copper instead of the plastic.

 

[Digiteeruk]

Well, as you can see from the diagram, fitting a room stat after the programmer would seem an immediate improvement and is a very easy / cheap DIY job (£14 or thereabouts) and must help with economy / comfort levels.

Installing a cylinder stat would seem like a very good idea too when linked to a new zone valve or you really have no direct control over cyl temp.

I'd get a couple of quotes from a Heating Engineer to supply a zone valve to isolate the cylinder when it reaches your required temp and you're away, unless more experienced members would advise differently?