Range FlowMax - Drain Radiator Circuit Only

[356Speedster]

Hi,

When we moved into our house 5mths ago, we found that the heating was pretty rubbish. Many of the TRVs were broken, some Lockshield valves were seized, rads were not heating up uniformly, etc. Also, we only have TRVs on about 60% of the rads making individual room control a bit tricky.

Now that the weather is warm enough, I'm planning on giving the rads a bit of TLC. The plan was as follows:
1. Part drain some of the system and add some Sentinel X400 to the system
2. Run the heating for 10-15mins over a few days to pump it round and give it chance to work
3. After a week or so, drain the radiator circuit
4. One by one, remove each radiator, take it into the garden and flush it out with a hose
5. Replace TRV / Lockshield valves as appropriate

Simple plan made harder by the fact that we have a Range FlowMax system and draining the rads & tank means we have no hot water until such a point as it's all put back together and re-filled.

As it takes about 1.5hrs to empty the whole system and just as long to re-fill, I don't really have much time to take off each rad, flush it out and replace the valves. Wifey will not tolerate no hot water in an evening (wimp I know!) and I don't want to be emptying / re-filling the system multiple times as I get around the 16 radiators in the house.

Working on my own and not knowing if I'm going to find any problems as I remove each valve, I don't know how much time this little task is going to take...

So, I'm calling on any FlowMax experts that might be out there to ask for advice. Is there a way of isolating the radiator flow circuit form the tank store, so I can take my time???

There's no obvious cut-off / service valves in the airing cupboard, but underneath, the pump does have them. This means I can cut off the flow side, but I dont' know if there's a way of isolating the return.

Would the system have a one-way valve on the return anyway preventing backwards flow? If it did, would it be safe to turn off the service valves at the pump, empty the rads, do my work over the period of a few days / a week (without therefore affecting the hot water side), then once I'm done, empty the remaiing water in the tank before re-filling the system?

Any advice would be much appreciated.

Thanks,

Mark

 

[gas4you]

I can't see any reason why you could drain and tempoararily cap off flow and return pipes to heating with say speedfit 22mm stop ends, possilby use one stop end on the flow and a 22mm coupling, 22-15 reducer and a speedfit drain off into the 15mm to let you drain again easy later.

I do not know the flowmax intimatley but if it has a seperate primary pump and circuit form the boiler as a boilermate then it should be ok.

Make sure you try to flush out and cleanse the flowmax as it is probably storing loads of crud in the bottom. I hope it is not designed like an old boilermate as their fill goes to the bottom and always blocks up so you can't refill it easily

 

[356Speedster]

Thanks Dave. If I can't find an isolation point for the radiator return circuit, I guess I could drain the whole lot down, split the return pipe and then add a service valve as per your recommendation.

In doing that, I would definately have the radiator circuit isolated for feed & return and still be able to utilise hot water.

Cheers,

Mark

 

[Agile]

Fit full flow valves in flow and return then you can repressurise the boiler and have DHW.

Tony