why does my heating pitch??

beanie10

Hi lads hopefully someone here knows what the problem is.

I have a heating system as follows:
oil burner split into 2 zones ( heating & hot water)
Solid fuel stove with pipe stat set to 55 deg.
House is a 4 bed bungalow.

Oil works perfect on its own & stove works perfect on its own. The problem is when stove is warm and i boost the oil burner for a bit of heat before bed the system starts to pitch.

When I light the stove in the evening I also turn on oil for 1 hour to get rads hot so stove can keep them warm for rest of evening. No pitching occurs in this hour, however when stove gets up to temperature and oil is on it starts pitching.

Its a dual coil cylinder 1 for oil and 1 for stove.

I would appreciate any help that could solve this problem.

shane0007

Could be a number of reasons. Incorrect position of f & e pipe, incorrect position of osvp, not enough head between the highest point of system & the f & e tank or too high a level of water in the f & e tank.
Check the latter first as this is a common issue. Water level should be 100mm from the bottom of the tank when the system is cold.

Billy Bunting

Pitching or boiling over ?? No thermostatic control over the stove, turning the stat down on the oil may help but then your gona miss it when on oil only. Usually this can also cause hi limit stat cutting out.

beanie10

Thanks Shane. No very little water in tank when cold. The water that pitches out is stone cold.
It only seems to happen when 2 pumps come on together.

aujopimur

If the cold feeds were installed correctly, ie connected in front of the pumps as they should have been, the system would not pitch.

cranefly

we have near enough the same set up, on very cold days we put the oil on for an hour or so before we light the stove, then after 40 mins or so of the stove getting up a good head of steam so to say, we hear the thermo for the stove click to say it is at 55 degrees and the stove pump comes on, we shut the oil off then as i dont think we should have both appliances on at the same time, although by then the rads are really hot, and the stove keeps them at 80 to 90% of the oil heat for the rest of the night which could be up to 8 hours, kick starting it with the oil really makes a difference, ours is a four bedroom dormer with 13 rads 5 of them are doubles, the stove is an esse 350gs inset stove which just slotted in to a regular fireplace, we have it over a year now and the difference to an ordinary fireplace is amazing. you should be wary though of some people saying that a stove will only use half the fuel of a normal fire, maybe for a roomheater only stove that could be true, but if you have a boiler stove heating a whole house, we have found that you may use the same amount of fuel or a little more than the old fireplace, but it is worth it, we only really had one room cosy and warm before we got the stove.