Central Heating pump question?

[nick69]

Hi guys,

I have a wood burning stove in my living room with back boiler attached which is plumbed in 28mm to gravity fed DHW with a heat dump radiator.
Im having 3 more rads installed upstairs on a pumped circuit which will be teed off the 28mm flow and return pipes to/from the wood burner.

Now I know this may sound like a stupid question but when the stat, which will be attached to the cylinder, tells the pump to turn on, will it run constantly or do they have a natural on-off-on type of running method?

How loud will the pump be if its running for 2-3 hours?

Thanks

 

[cider]

No disrespect but does whoever is carrying out this work no what they are doing ? Putting three rads onto an existing wood burner is a massive extra demand on the output of the stove. So either the stove is continually boiling at the moment or you plan on having luke warm radiators especially if your pumping them. Whats the idea of the stat on the cylinder? is it going to start the pump when the tanks hot ? I presume the rads will be joined into the existing gravity circuit with an injector tee to prevent robbing the cylinder of heat. Also pumping a back boiler circuit which has insufficient output will result in condensation on the boiler surface leading to premature boiler failure unless you fit a low limit pipe stat to controll the pump.
Also is the cylinder indirect or twin feed as the later will not be suitable.