What plan do I have?

[ericmark]

Bosch oil fired boiler, two pumps, domestic hot water thermo siphon, one thermostat, and a controller with 6 options, off, on, Hot water and central heating once, Hot water and central heating twice, Hot water twice and central heating once, Hot water once and central heating twice.

I suspect there was a second thermostat which has been removed.

What I want is a domestic hot water only option, and some means to turn it off once the cistern is hot.

Want to keep it using a standard system so when I am older or dead, some one else can maintain it. It seems no motorised valves so no micro switches to relay to start boiler.

I have a spare PLC so I could design a system to do all required, but then in the future some one will be scratching their head, so want to keep it as standard as possible.

 

[Razor900]

Are you saying you have two heating zones?

Unless one pump is for DHW or redundant.....

 

[ericmark]

Yes two heating zones, bottom floor is old granny flat, and the pump is on a plug and socket, unplugging stops the flat radiators working, there are two thermostats one mechanical and one can hear it click, but seems to have no effect, second very old wireless receiver not found any transmitter, just 4 holes in wall where it likely was. The time clock

Is rather old and has no option for hot water only, the instructions say turn down thermostat. There is no tank thermostat.

I can modify and make it work, that's not a problem. However I would like to follow a standard plan so some one else has a chance of working out what I have done.

For summer some form of tank thermostat is required. In winter not so important.

So I suspect each pump will need a thermostat, a thermostat with double pole would be best, but relay would work instead, hot water simple thermostat in parallel with relays. It would work, but better if following a standard design.

 

[Johnmdc]

On your clock at the 4 o'clock position it says H off W twice so in that position the heating will be off. Then you can use the boiler thermostat to control the hot water temperature for the summer until you sort it all out.

 

[ericmark]

On your clock at the 4 o'clock position it says H off W twice so in that position the heating will be off. Then you can use the boiler thermostat to control the hot water temperature for the summer until you sort it all out.

Yes it says that, but upstairs radiators get hot, and centre floor radiators get look warm. Fitted smart socket to one of the pump feeds so I can turn off heating the granny flat now, simple push of a button to turn on again.

 

[Razor900]

Sounds more like the gravity check valve on the flow to the heating is either seized or missing altogether. Fit a new one and your rad thermosyphoning problems may well go away

 

[ericmark]

Sounds more like the gravity check valve on the flow to the heating is either seized or missing altogether. Fit a new one and your rad thermosyphoning problems may well go away

That makes sense, I will talk to plumber.

 

[ericmark]

Seems I have

and I want to convert that to

so it will not cycle once water is hot, I remember years ago getting a cheap wireless tank thermostat to do this with dad's old system, but can't seem to find cheap units any more. £125 seems a bit OTT for the conversion.

I guess I am using wrong wording on internet hunt?