gravity hot water?

jackben

Hi, just quick question about rads and the hot water cylinder connected to a stove. I was told the stove is plumbed in such a way that if the hot water cylinder will heat first on gravity before the pipe stat cuts in the pump to heat rads and if there was a power cut or pump problem etc the water could flow to the coil by gravity, but i have noticed when the stove is lit the coil remains cool until the pipe stat calls in the pump, does this mean that the hot water system isnot workin on gravity?. is there any physical way of seen this by looking at the pipes from the stove to the hot press.
many thanks

JohnnieK

jackben wrote: »

Hi, just quick question about rads and the hot water cylinder connected to a stove. I was told the stove is plumbed in such a way that if the hot water cylinder will heat first on gravity before the pipe stat cuts in the pump to heat rads and if there was a power cut or pump problem etc the water could flow to the coil by gravity, but i have noticed when the stove is lit the coil remains cool until the pipe stat calls in the pump, does this mean that the hot water system isnot workin on gravity?. is there any physical way of seen this by looking at the pipes from the stove to the hot press.
many thanks

Having a stab I would say yes your coil is not on Gravity, of course it's hard to give advice with out seeing the installation. Could you take some photo's and post them.

jackben

thanks

JohnnieK

On the 3rd picture the 1" pipe appears to be dropping slightly as it comes along (could be the angle of the photo) and is the stove to the right of the shot? if it is the pipe should be always rising slightly up to the coil, I would say this is your problem and when the pump is activated it is working on circulation like the rest of the system. It is a very neat installation and the plumber should be congratulated. There is a lot of fellas out there just throwing the work in.

Also on the first pic the cable retainer is not in place on the pipe stat, and the safety valve is not piped outside

DoneDL

jackben, has the stove been set up with four connections to the cylinder and is the pump on the heating side of the stove.

jackben

hi,there is 2 coils in cylinder ,one from stove one from heating,the pump is on return pipe just behind the stove

DoneDL

DoneDL wrote: »

jackben, has the stove been set up with four connections to the cylinder stove and is the pump on the heating side of the stove.

has the stove been set up with four connections to the stove and is the pump on the heating side of the stove. Apologies I meant to post about connections to the stove.

jackben

no there is 2 1 inch pipes from stove to coil these pipes are connected diagonally at back of stove.

bcool

jackben wrote: »

no there is 2 1 inch pipes from stove to coil these pipes are connected diagonally at back of stove.

Hi
I dont know if this is any help but i have just installed a stove and on the installation manual they recomend having pipe stat on return pipe. ie pipe leaving cylinder to go back to stove. But plumber says he always puts it on feed to cylinder. This is the way i have it at fitted now, and no probs.

I was also worried about gravity feed as i live in Bungalow and had issues with water going up to attic and then back down to cylinder. So to test it worked , I turned off power to pump, had fire roaring, and it worked no prob.

Try this if you want, but do not leave house. If u hear banging etc. turn power back on to pump.

bcool

DoneDL

jackben, I would consider relocating the pump. The flow and return to the cylinder should be unrestricted.

JohnnieK

DoneDL wrote: »

jackben, I would consider relocating the pump. The flow and return to the cylinder should be unrestricted.

I agree. The pump would be causing some amount of resistance on the gravity circuit.

jackben

OK thanks for all the helpful replies,first ignore the bottom pipe stat with cable gland out as its not wired and I'm in the process of getting a route outside for the 3 bar pressure relief valve outlet,also if the pump is taken off the return from cylinder coil where can it be positioned and finally if i ensure all flow pipework coming from stove to coil is level or rising slightly to wards the coil will this ensure gravity circulation or do i need to take into account the return pipe from coil to stove also?Hope these questions make sense.

DoneDL

jackben, I can`t make out where your heating pipework meets your stove pipework. But if I was doing that system I would put an injection tee where the lowest elbow is on the return at the cylinder and position the pump on the heating side of the tee pumping into the stove. That said I also cannot see your feed and vent pipes to the cylinder so it`s really difficult to be sure.

jackben

Some more pics