Secondary Pump and Timer

[SnowHouse]

Just moved into a big modern house with hi end fixtures and fittings. Gas boiler with under floor heating and a secondary hot water system. I found 3 timers. The one labelled “towel rads” obviously controls when these are heated. I am assuming the one labelled “HW” controls when the boiler fires up to heat the water and the one labelled “secondary” controls the pump for hot water circulation.

Q1. Should the secondary pump timer be set for the same times as the hot water? If so, why are 2 timers needed?

Q2. Should there be a primary pump and timer somewhere?

Q3. I have not found a timer for the central heating boiler function. Is this normal? Ie boiler left on full time only switching off when every room stat has reached its target temperature?

I attach some pictures

 

[ericmark]

This is my worry with my own system, will when I get older, some one else be able to work out what I have?

In the main UFH has a pump which circulates water around the UFH system, and as the water cools more hot is added and some cool is returned to be re-heated. This exchange is done with a second pump, but it seems you have at least 4 pumps.

So I would guess you have a heat store, and the boiler heats the store, and the store heats everything else, this is often done where one have multi fuels used,

This one uses 3 pumps, not my drawing, but once drawn out reasonably easy to follow, but to reverse engineer is a lot harder, and this only shows the pipe work, the control is another thing, I tried to design my system and to draw it out, my first attempt I made an error, and then realised I needed relays so pump and boiler independent.

The easy way is a controller like this which has all the relays built in, but the best option is to look for the installers name, often there is a sticker saying call xxxxxx for service, I would find it hard enough to work out when I can feel when a pump runs or motorised valve operates, and which pipes are getting hot. To do it from pictures is not really going to happen.

 

[ScottishGasMan]

Q1. Should the secondary pump timer be set for the same times as the hot water? If so, why are 2 timers needed?

Q2. Should there be a primary pump and timer somewhere?

Q3. I have not found a timer for the central heating boiler function. Is this normal? Ie boiler left on full time only switching off when every room stat has reached its target temperature?

Q1 No.
Q2 No
Q3 They should have time control over the heating zones yes.

 

[Exedon]

The green/bronze pump above the hot water cylinder is a secondary circulator so you get almost instant hot water through the house.
It needs timing on for whenever you normally have a hot demand. Certainly needs to be off over night unless the hot water pipework is extremely well insulated they tend to waste heat.

 

[ScottishGasMan]

unless the hot water pipework is extremely well insulated

Going by the rest of the lagging and pipes in that pic I think its a safe bet it's not extremely well insulated lol.